Core: Combat/threat system rewrite (PR #19930)

- PvE combat is now always mutual. UNIT_FLAG_IN_COMBAT is backed by actual references to the units we're in combat with.
- PvP combat is now also tracked, and almost always mutual; spells like Vanish and Feign Death can break this rule. That means we can easily determine a list of players we're fighting.
- By extension, IsInCombatWith now has sensible behavior when invoked on nonplayers.
- Threat and combat systems are no longer the same.
  - They still have an enforced relationship (threat implies combat - clearing combat clears threat)...
  - ...but we can have combat without threat. A creature (with threat list) isn't considered to be engaged until it has an entry on its threat list...
  - ...which means we can now faithfully replicate retail engage behavior. Combat on projectile launch - engagement start on projectile impact. Yay for progress!
- AI method refactor, as already ported in 6113b9d - `JustEngagedWith`, `JustEnteredCombat` and `JustExitedCombat`.
- Vehicle threat is now properly pooled on the main vehicle body (fixes #16542).
- Various edge case bug fixes for threat redirects (Misdirection "cancelling" Vigilance and similar).
- Target re-selection is now significantly faster.
- Fixed a ton of other smaller edge case bugs, probably.

Closes #7951 and #19998.

(cherry picked from commit 532ab1c7f8653d1a2e48aa1f1f8a9ba1041d4bb7)

57 files changed, 2042 insertions, 2194 deletions

diff --git a/src/server/game/AI/CoreAI/PetAI.cpp b/src/server/game/AI/CoreAI/PetAI.cpp
index 2a2b8c62bd3..50cad20bae1 100644
--- a/src/server/game/AI/CoreAI/PetAI.cpp
+++ b/src/server/game/AI/CoreAI/PetAI.cpp
@@ -69,7 +69,6 @@ void PetAI::_stopAttack()
         me->GetMotionMaster()->Clear();
         me->GetMotionMaster()->MoveIdle();
         me->CombatStop();
-        me->getHostileRefManager().deleteReferences();
         return;
     }
 
@@ -459,8 +458,7 @@ void PetAI::HandleReturnMovement()
             me->GetMotionMaster()->MoveFollow(me->GetCharmerOrOwner(), PET_FOLLOW_DIST, me->GetFollowAngle());
         }
     }
-
-    me->ClearInPetCombat();
+    me->RemoveUnitFlag(UNIT_FLAG_PET_IN_COMBAT); // on player pets, this flag indicates that we're actively going after a target - we're returning, so remove it
 }
 
 void PetAI::DoAttack(Unit* target, bool chase)
@@ -470,12 +468,7 @@ void PetAI::DoAttack(Unit* target, bool chase)
 
     if (me->Attack(target, true))
     {
-        // properly fix fake combat after pet is sent to attack
-        if (Unit* owner = me->GetOwner())
-            owner->AddUnitFlag(UNIT_FLAG_PET_IN_COMBAT);
-
-        me->AddUnitFlag(UNIT_FLAG_PET_IN_COMBAT);
-
+        me->AddUnitFlag(UNIT_FLAG_PET_IN_COMBAT); // on player pets, this flag indicates we're actively going after a target - that's what we're doing, so set it
         // Play sound to let the player know the pet is attacking something it picked on its own
         if (me->HasReactState(REACT_AGGRESSIVE) && !me->GetCharmInfo()->IsCommandAttack())
             me->SendPetAIReaction(me->GetGUID());
diff --git a/src/server/game/AI/CoreAI/UnitAI.h b/src/server/game/AI/CoreAI/UnitAI.h
index b2cf0564546..30fa8a56958 100644
--- a/src/server/game/AI/CoreAI/UnitAI.h
+++ b/src/server/game/AI/CoreAI/UnitAI.h
@@ -19,6 +19,7 @@
 #define TRINITY_UNITAI_H
 
 #include "Containers.h"
+#include "Errors.h"
 #include "EventMap.h"
 #include "ObjectGuid.h"
 #include "SpellDefines.h"
diff --git a/src/server/game/AI/CreatureAI.cpp b/src/server/game/AI/CreatureAI.cpp
index 1b7234dd939..2c07dcd551d 100644
--- a/src/server/game/AI/CreatureAI.cpp
+++ b/src/server/game/AI/CreatureAI.cpp
@@ -67,61 +67,49 @@ void CreatureAI::DoZoneInCombat(Creature* creature /*= nullptr*/, float maxRange
     if (!creature)
         creature = me;
 
-    if (!creature->CanHaveThreatList())
-        return;
-
     Map* map = creature->GetMap();
-    if (!map->IsDungeon())                                  //use IsDungeon instead of Instanceable, in case battlegrounds will be instantiated
+    if (creature->CanHaveThreatList())
     {
-        TC_LOG_ERROR("misc", "DoZoneInCombat call for map that isn't an instance (creature entry = %d)", creature->GetTypeId() == TYPEID_UNIT ? creature->ToCreature()->GetEntry() : 0);
-        return;
-    }
+        if (!map->IsDungeon())                                  //use IsDungeon instead of Instanceable, in case battlegrounds will be instantiated
+        {
+            TC_LOG_ERROR("misc", "DoZoneInCombat call for map that isn't an instance (creature entry = %d)", creature->GetTypeId() == TYPEID_UNIT ? creature->ToCreature()->GetEntry() : 0);
+            return;
+        }
 
-    if (!creature->HasReactState(REACT_PASSIVE) && !creature->GetVictim())
-    {
-        if (Unit* nearTarget = creature->SelectNearestTarget(maxRangeToNearestTarget))
-            creature->AI()->AttackStart(nearTarget);
-        else if (creature->IsSummon())
+        if (!creature->HasReactState(REACT_PASSIVE) && !creature->GetVictim())
         {
-            if (Unit* summoner = creature->ToTempSummon()->GetSummoner())
+            if (Unit* nearTarget = creature->SelectNearestTarget(maxRangeToNearestTarget))
+                creature->AI()->AttackStart(nearTarget);
+            else if (creature->IsSummon())
             {
-                Unit* target = summoner->getAttackerForHelper();
-                if (!target && summoner->CanHaveThreatList() && !summoner->GetThreatManager().IsThreatListEmpty())
-                    target = summoner->GetThreatManager().GetAnyTarget();
-                if (target && (creature->IsFriendlyTo(summoner) || creature->IsHostileTo(target)))
-                    creature->AI()->AttackStart(target);
+                if (Unit* summoner = creature->ToTempSummon()->GetSummoner())
+                {
+                    Unit* target = summoner->getAttackerForHelper();
+                    if (!target && !summoner->GetThreatManager().IsThreatListEmpty())
+                        target = summoner->GetThreatManager().GetAnyTarget();
+                    if (target && (creature->IsFriendlyTo(summoner) || creature->IsHostileTo(target)))
+                        creature->AI()->AttackStart(target);
+                }
             }
         }
-    }
 
-    // Intended duplicated check, the code above this should select a victim
-    // If it can't find a suitable attack target then we should error out.
-    if (!creature->HasReactState(REACT_PASSIVE) && !creature->GetVictim())
-    {
-        TC_LOG_ERROR("misc.dozoneincombat", "DoZoneInCombat called for creature that has empty threat list (creature entry = %u)", creature->GetEntry());
-        return;
+        // Intended duplicated check, the code above this should select a victim
+        // If it can't find a suitable attack target then we should error out.
+        if (!creature->HasReactState(REACT_PASSIVE) && !creature->GetVictim())
+        {
+            TC_LOG_ERROR("misc.dozoneincombat", "DoZoneInCombat called for creature that has empty threat list (creature entry = %u)", creature->GetEntry());
+            return;
+        }
     }
 
     Map::PlayerList const& playerList = map->GetPlayers();
-
     if (playerList.isEmpty())
         return;
 
     for (Map::PlayerList::const_iterator itr = playerList.begin(); itr != playerList.end(); ++itr)
-    {
         if (Player* player = itr->GetSource())
-        {
-            if (player->IsGameMaster())
-                continue;
-
             if (player->IsAlive())
-            {
                 creature->SetInCombatWith(player);
-                player->SetInCombatWith(creature);
-                creature->GetThreatManager().AddThreat(player, 0.0f, nullptr, true, true);
-            }
-        }
-    }
 }
 
 // scripts does not take care about MoveInLineOfSight loops
@@ -249,11 +237,13 @@ bool CreatureAI::UpdateVictim()
 
         return me->GetVictim() != nullptr;
     }
-    else if (me->GetThreatManager().IsThreatListEmpty())
+    else if (me->GetThreatManager().IsThreatListEmpty(true))
     {
         EnterEvadeMode(EVADE_REASON_NO_HOSTILES);
         return false;
     }
+    else
+        me->AttackStop();
 
     return true;
 }
diff --git a/src/server/game/AI/PlayerAI/PlayerAI.h b/src/server/game/AI/PlayerAI/PlayerAI.h
index 600713e9680..195f7cb03b2 100644
--- a/src/server/game/AI/PlayerAI/PlayerAI.h
+++ b/src/server/game/AI/PlayerAI/PlayerAI.h
@@ -20,6 +20,7 @@
 
 #include "UnitAI.h"
 
+class Creature;
 class Spell;
 
 class TC_GAME_API PlayerAI : public UnitAI
diff --git a/src/server/game/AI/ScriptedAI/ScriptedCreature.cpp b/src/server/game/AI/ScriptedAI/ScriptedCreature.cpp
index fc5e30d0ff1..d502e70fa7e 100644
--- a/src/server/game/AI/ScriptedAI/ScriptedCreature.cpp
+++ b/src/server/game/AI/ScriptedAI/ScriptedCreature.cpp
@@ -504,11 +504,12 @@ void BossAI::TeleportCheaters()
     float x, y, z;
     me->GetPosition(x, y, z);
 
-    ThreatContainer::StorageType threatList = me->GetThreatManager().getThreatList();
-    for (ThreatContainer::StorageType::const_iterator itr = threatList.begin(); itr != threatList.end(); ++itr)
-        if (Unit* target = (*itr)->getTarget())
-            if (target->GetTypeId() == TYPEID_PLAYER && !CheckBoundary(target))
-                target->NearTeleportTo(x, y, z, 0);
+    for (auto const& pair : me->GetCombatManager().GetPvECombatRefs())
+    {
+        Unit* target = pair.second->GetOther(me);
+        if (target->IsControlledByPlayer() && !CheckBoundary(target))
+            target->NearTeleportTo(x, y, z, 0);
+    }
 }
 
 void BossAI::JustSummoned(Creature* summon)
diff --git a/src/server/game/AI/ScriptedAI/ScriptedCreature.h b/src/server/game/AI/ScriptedAI/ScriptedCreature.h
index 5556f24872b..4e41082f561 100644
--- a/src/server/game/AI/ScriptedAI/ScriptedCreature.h
+++ b/src/server/game/AI/ScriptedAI/ScriptedCreature.h
@@ -184,7 +184,7 @@ struct TC_GAME_API ScriptedAI : public CreatureAI
     void Reset() override { }
 
     //Called at creature aggro either by MoveInLOS or Attack Start
-    void JustEngagedWith(Unit* /*victim*/) override { }
+    void JustEngagedWith(Unit* /*who*/) override { }
 
     // Called before JustEngagedWith even before the creature is in combat.
     void AttackStart(Unit* /*target*/) override;
diff --git a/src/server/game/AI/SmartScripts/SmartScript.cpp b/src/server/game/AI/SmartScripts/SmartScript.cpp
index 4192a243367..36084e06989 100644
--- a/src/server/game/AI/SmartScripts/SmartScript.cpp
+++ b/src/server/game/AI/SmartScripts/SmartScript.cpp
@@ -2254,6 +2254,8 @@ void SmartScript::ProcessAction(SmartScriptHolder& e, Unit* unit, uint32 var0, u
         }
         case SMART_ACTION_ADD_THREAT:
         {
+            if (!me->CanHaveThreatList())
+                break;
             for (WorldObject* const target : targets)
                 if (IsUnit(target))
                     me->GetThreatManager().AddThreat(target->ToUnit(), float(e.action.threatPCT.threatINC) - float(e.action.threatPCT.threatDEC), nullptr, true, true);
diff --git a/src/server/game/Battlegrounds/Battleground.cpp b/src/server/game/Battlegrounds/Battleground.cpp
index b9cac4f0254..91871e1edd8 100644
--- a/src/server/game/Battlegrounds/Battleground.cpp
+++ b/src/server/game/Battlegrounds/Battleground.cpp
@@ -768,11 +768,8 @@ void Battleground::EndBattleground(uint32 winner)
             player->SpawnCorpseBones();
         }
         else
-        {
             //needed cause else in av some creatures will kill the players at the end
             player->CombatStop();
-            player->getHostileRefManager().deleteReferences();
-        }
 
         // remove temporary currency bonus auras before rewarding player
         player->RemoveAura(SPELL_HONORABLE_DEFENDER_25Y);
diff --git a/src/server/game/Combat/CombatManager.cpp b/src/server/game/Combat/CombatManager.cpp
new file mode 100644
index 00000000000..3bd5f70cd7e
--- /dev/null
+++ b/src/server/game/Combat/CombatManager.cpp
@@ -0,0 +1,350 @@
+/*
+ * This file is part of the TrinityCore Project. See AUTHORS file for Copyright information
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the
+ * Free Software Foundation; either version 2 of the License, or (at your
+ * option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "CombatManager.h"
+#include "Creature.h"
+#include "CreatureAI.h"
+#include "Player.h"
+
+/*static*/ bool CombatManager::CanBeginCombat(Unit const* a, Unit const* b)
+{
+    // Checks combat validity before initial reference creation.
+    // For the combat to be valid...
+    // ...the two units need to be different
+    if (a == b)
+        return false;
+    // ...the two units need to be in the world
+    if (!a->IsInWorld() || !b->IsInWorld())
+        return false;
+    // ...the two units need to both be alive
+    if (!a->IsAlive() || !b->IsAlive())
+        return false;
+    // ...the two units need to be on the same map
+    if (a->GetMap() != b->GetMap())
+        return false;
+    // ...the two units need to be in the same phase
+    if (!WorldObject::InSamePhase(a, b))
+        return false;
+    if (a->HasUnitState(UNIT_STATE_EVADE) || b->HasUnitState(UNIT_STATE_EVADE))
+        return false;
+    if (a->HasUnitState(UNIT_STATE_IN_FLIGHT) || b->HasUnitState(UNIT_STATE_IN_FLIGHT))
+        return false;
+    if (a->IsControlledByPlayer() || b->IsControlledByPlayer())
+    { // PvSomething, only block friendly fire
+        if (a->IsFriendlyTo(b) || b->IsFriendlyTo(a))
+            return false;
+    }
+    else
+    { // CvC, need hostile reaction to start a fight
+        if (!a->IsHostileTo(b) && !b->IsHostileTo(a))
+            return false;
+    }
+    Player const* playerA = a->GetCharmerOrOwnerPlayerOrPlayerItself();
+    Player const* playerB = b->GetCharmerOrOwnerPlayerOrPlayerItself();
+    // ...neither of the two units must be (owned by) a player with .gm on
+    if ((playerA && playerA->IsGameMaster()) || (playerB && playerB->IsGameMaster()))
+        return false;
+    return true;
+}
+
+void CombatReference::EndCombat()
+{
+    // sequencing matters here - AI might do nasty stuff, so make sure refs are in a consistent state before you hand off!
+
+    // first, get rid of any threat that still exists...
+    first->GetThreatManager().ClearThreat(second);
+    second->GetThreatManager().ClearThreat(first);
+
+    // ...then, remove the references from both managers...
+    first->GetCombatManager().PurgeReference(second->GetGUID(), _isPvP);
+    second->GetCombatManager().PurgeReference(first->GetGUID(), _isPvP);
+
+    // ...update the combat state, which will potentially remove IN_COMBAT...
+    bool const needFirstAI = first->GetCombatManager().UpdateOwnerCombatState();
+    bool const needSecondAI = second->GetCombatManager().UpdateOwnerCombatState();
+
+    // ...and if that happened, also notify the AI of it...
+    if (needFirstAI && first->IsAIEnabled)
+        first->GetAI()->JustExitedCombat();
+    if (needSecondAI && second->IsAIEnabled)
+        second->GetAI()->JustExitedCombat();
+
+    // ...and finally clean up the reference object
+    delete this;
+}
+
+bool PvPCombatReference::Update(uint32 tdiff)
+{
+    if (_combatTimer <= tdiff)
+        return false;
+    _combatTimer -= tdiff;
+    return true;
+}
+
+void PvPCombatReference::Refresh()
+{
+    _combatTimer = PVP_COMBAT_TIMEOUT;
+
+    bool needFirstAI = false, needSecondAI = false;
+    if (_suppressFirst)
+    {
+        _suppressFirst = false;
+        needFirstAI = first->GetCombatManager().UpdateOwnerCombatState();
+    }
+    if (_suppressSecond)
+    {
+        _suppressSecond = false;
+        needSecondAI = second->GetCombatManager().UpdateOwnerCombatState();
+    }
+
+    if (needFirstAI)
+        CombatManager::NotifyAICombat(first, second);
+    if (needSecondAI)
+        CombatManager::NotifyAICombat(second, first);
+}
+
+void PvPCombatReference::SuppressFor(Unit* who)
+{
+    Suppress(who);
+    if (who->GetCombatManager().UpdateOwnerCombatState())
+        if (who->IsAIEnabled)
+            who->GetAI()->JustExitedCombat();
+}
+
+void CombatManager::Update(uint32 tdiff)
+{
+    auto it = _pvpRefs.begin(), end = _pvpRefs.end();
+    while (it != end)
+    {
+        PvPCombatReference* const ref = it->second;
+        if (ref->first == _owner && !ref->Update(tdiff)) // only update if we're the first unit involved (otherwise double decrement)
+        {
+            it = _pvpRefs.erase(it), end = _pvpRefs.end(); // remove it from our refs first to prevent invalidation
+            ref->EndCombat(); // this will remove it from the other side
+        }
+        else
+            ++it;
+    }
+}
+
+bool CombatManager::HasPvPCombat() const
+{
+    for (auto const& pair : _pvpRefs)
+        if (!pair.second->IsSuppressedFor(_owner))
+            return true;
+    return false;
+}
+
+Unit* CombatManager::GetAnyTarget() const
+{
+    if (!_pveRefs.empty())
+        return _pveRefs.begin()->second->GetOther(_owner);
+    for (auto const& pair : _pvpRefs)
+        if (!pair.second->IsSuppressedFor(_owner))
+            return pair.second->GetOther(_owner);
+    return nullptr;
+}
+
+bool CombatManager::SetInCombatWith(Unit* who)
+{
+    // Are we already in combat? If yes, refresh pvp combat
+    auto it = _pvpRefs.find(who->GetGUID());
+    if (it != _pvpRefs.end())
+    {
+        it->second->Refresh();
+        return true;
+    }
+    else if (_pveRefs.find(who->GetGUID()) != _pveRefs.end())
+        return true;
+
+    // Otherwise, check validity...
+    if (!CombatManager::CanBeginCombat(_owner, who))
+        return false;
+
+    // ...then create new reference
+    CombatReference* ref;
+    if (_owner->IsControlledByPlayer() && who->IsControlledByPlayer())
+        ref = new PvPCombatReference(_owner, who);
+    else
+        ref = new CombatReference(_owner, who);
+
+    // ...and insert it into both managers
+    PutReference(who->GetGUID(), ref);
+    who->GetCombatManager().PutReference(_owner->GetGUID(), ref);
+
+    // now, sequencing is important - first we update the combat state, which will set both units in combat and do non-AI combat start stuff
+    bool const needSelfAI  = UpdateOwnerCombatState();
+    bool const needOtherAI = who->GetCombatManager().UpdateOwnerCombatState();
+
+    // then, we finally notify the AI (if necessary) and let it safely do whatever it feels like
+    if (needSelfAI)
+        NotifyAICombat(_owner, who);
+    if (needOtherAI)
+        NotifyAICombat(who, _owner);
+    return true;
+}
+
+bool CombatManager::IsInCombatWith(ObjectGuid const& guid) const
+{
+    return (_pveRefs.find(guid) != _pveRefs.end()) || (_pvpRefs.find(guid) != _pvpRefs.end());
+}
+
+bool CombatManager::IsInCombatWith(Unit const* who) const
+{
+    return IsInCombatWith(who->GetGUID());
+}
+
+void CombatManager::InheritCombatStatesFrom(Unit const* who)
+{
+    CombatManager const& mgr = who->GetCombatManager();
+    for (auto& ref : mgr._pveRefs)
+    {
+        if (!IsInCombatWith(ref.first))
+        {
+            Unit* target = ref.second->GetOther(who);
+            if ((_owner->IsImmuneToPC() && target->HasUnitFlag(UNIT_FLAG_PVP_ATTACKABLE)) ||
+                (_owner->IsImmuneToNPC() && !target->HasUnitFlag(UNIT_FLAG_PVP_ATTACKABLE)))
+                continue;
+            SetInCombatWith(target);
+        }
+    }
+    for (auto& ref : mgr._pvpRefs)
+    {
+        if (!IsInCombatWith(ref.first))
+        {
+            Unit* target = ref.second->GetOther(who);
+            if ((_owner->IsImmuneToPC() && target->HasUnitFlag(UNIT_FLAG_PVP_ATTACKABLE)) ||
+                (_owner->IsImmuneToNPC() && !target->HasUnitFlag(UNIT_FLAG_PVP_ATTACKABLE)))
+                continue;
+            SetInCombatWith(target);
+        }
+    }
+}
+
+void CombatManager::EndCombatBeyondRange(float range, bool includingPvP)
+{
+    auto it = _pveRefs.begin(), end = _pveRefs.end();
+    while (it != end)
+    {
+        CombatReference* const ref = it->second;
+        if (!ref->first->IsWithinDistInMap(ref->second, range))
+        {
+            it = _pveRefs.erase(it), end = _pveRefs.end(); // erase manually here to avoid iterator invalidation
+            ref->EndCombat();
+        }
+        else
+            ++it;
+    }
+
+    if (!includingPvP)
+        return;
+
+    auto it2 = _pvpRefs.begin(), end2 = _pvpRefs.end();
+    while (it2 != end2)
+    {
+        CombatReference* const ref = it2->second;
+        if (!ref->first->IsWithinDistInMap(ref->second, range))
+        {
+            it2 = _pvpRefs.erase(it2), end2 = _pvpRefs.end(); // erase manually here to avoid iterator invalidation
+            ref->EndCombat();
+        }
+        else
+            ++it2;
+    }
+}
+
+void CombatManager::SuppressPvPCombat()
+{
+    for (auto const& pair : _pvpRefs)
+        pair.second->Suppress(_owner);
+    if (UpdateOwnerCombatState())
+        if (_owner->IsAIEnabled)
+            _owner->GetAI()->JustExitedCombat();
+}
+
+void CombatManager::EndAllPvECombat()
+{
+    // cannot have threat without combat
+    _owner->GetThreatManager().RemoveMeFromThreatLists();
+    _owner->GetThreatManager().ClearAllThreat();
+    while (!_pveRefs.empty())
+        _pveRefs.begin()->second->EndCombat();
+}
+
+void CombatManager::EndAllPvPCombat()
+{
+    while (!_pvpRefs.empty())
+        _pvpRefs.begin()->second->EndCombat();
+}
+
+/*static*/ void CombatManager::NotifyAICombat(Unit* me, Unit* other)
+{
+    if (!me->IsAIEnabled)
+        return;
+    me->GetAI()->JustEnteredCombat(other);
+
+    if (Creature* cMe = me->ToCreature())
+        if (!cMe->CanHaveThreatList())
+            cMe->AI()->JustEngagedWith(other);
+}
+
+void CombatManager::PutReference(ObjectGuid const& guid, CombatReference* ref)
+{
+    if (ref->_isPvP)
+    {
+        auto& inMap = _pvpRefs[guid];
+        ASSERT(!inMap && "Duplicate combat state detected - memory leak!");
+        inMap = static_cast<PvPCombatReference*>(ref);
+    }
+    else
+    {
+        auto& inMap = _pveRefs[guid];
+        ASSERT(!inMap && "Duplicate combat state detected - memory leak!");
+        inMap = ref;
+    }
+}
+
+void CombatManager::PurgeReference(ObjectGuid const& guid, bool pvp)
+{
+    if (pvp)
+        _pvpRefs.erase(guid);
+    else
+        _pveRefs.erase(guid);
+}
+
+bool CombatManager::UpdateOwnerCombatState() const
+{
+    bool const combatState = HasCombat();
+    if (combatState == _owner->IsInCombat())
+        return false;
+
+    if (combatState)
+    {
+        _owner->AddUnitFlag(UNIT_FLAG_IN_COMBAT);
+        _owner->AtEnterCombat();
+    }
+    else
+    {
+        _owner->RemoveUnitFlag(UNIT_FLAG_IN_COMBAT);
+        _owner->AtExitCombat();
+    }
+
+    if (Unit* master = _owner->GetCharmerOrOwner())
+        master->UpdatePetCombatState();
+
+    return true;
+}
diff --git a/src/server/game/Combat/CombatManager.h b/src/server/game/Combat/CombatManager.h
new file mode 100644
index 00000000000..2b8e95ad220
--- /dev/null
+++ b/src/server/game/Combat/CombatManager.h
@@ -0,0 +1,143 @@
+/*
+ * This file is part of the TrinityCore Project. See AUTHORS file for Copyright information
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the
+ * Free Software Foundation; either version 2 of the License, or (at your
+ * option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef TRINITY_COMBATMANAGER_H
+#define TRINITY_COMBATMANAGER_H
+
+#include "Common.h"
+#include "ObjectGuid.h"
+#include <unordered_map>
+
+class Unit;
+
+/********************************************************************************************************************************************************\
+ *                                                           DEV DOCUMENTATION: COMBAT SYSTEM                                                           *
+ *                                            (future devs: please keep this up-to-date if you change the system)                                       *
+ * CombatManager maintains a list of dynamically allocated CombatReference entries. Each entry represents a combat state between two distinct units.    *
+ * A unit is "in combat" iff it has one or more non-suppressed CombatReference entries in its CombatManager. No exceptions.                             *
+ *   - Note: Only PvP combat references can be suppressed, and only because Vanish is a very silly spell. Sue Blizzard.                                 *
+ *                                                                                                                                                      *
+ * A CombatReference object carries the following implicit guarantees by existing:                                                                      *
+ *  - Both CombatReference.first and CombatReference.second are valid Units, distinct, not nullptr and currently in the world.                          *
+ *  - If the CombatReference was retrieved from the CombatManager of Unit* A, then exactly one of .first and .second is equal to A.                     *
+ *    - Note: Use CombatReference::GetOther to quickly get the other unit for a given reference.                                                        *
+ *  - Both .first and .second are currently in combat (IsInCombat will always be true) if either of the following hold:                                 *
+ *    - The reference is a PvE combat reference (_isPvP is false)                                                                                       *
+ *    - IsSuppressedFor returns false for the respective unit                                                                                           *
+ *                                                                                                                                                      *
+ * To end combat between two units, find their CombatReference and call EndCombat.                                                                      *
+ *  - Keep in mind that this modifies the CombatRefs maps on both ends, which may cause iterators to be invalidated.                                    *
+ *                                                                                                                                                      *
+ * To put two units in combat with each other, call SetInCombatWith. Note that this is not guaranteed to succeed.                                       *
+ *  - The return value of SetInCombatWith is the new combat state between the units (identical to calling IsInCombatWith at that time).                 *
+ *                                                                                                                                                      *
+ * Note that (threat => combat) is a strong guarantee provided in conjunction with ThreatManager. Thus:                                                 *
+ *  - Ending combat between two units will also delete any threat references that may exist between them.                                               *
+ *  - Adding threat will also create a combat reference between the units if one doesn't exist yet.                                                     *
+\********************************************************************************************************************************************************/
+
+// Please check Game/Combat/CombatManager.h for documentation on how this class works!
+struct TC_GAME_API CombatReference
+{
+    Unit* const first;
+    Unit* const second;
+    bool const _isPvP;
+    Unit* GetOther(Unit const* me) const { return (first == me) ? second : first; }
+
+    void EndCombat();
+
+    CombatReference(CombatReference const&) = delete;
+    CombatReference& operator=(CombatReference const&) = delete;
+
+protected:
+    CombatReference(Unit* a, Unit* b, bool pvp = false) : first(a), second(b), _isPvP(pvp) { }
+
+    friend class CombatManager;
+};
+
+// Please check Game/Combat/CombatManager.h for documentation on how this class works!
+struct TC_GAME_API PvPCombatReference : public CombatReference
+{
+    static const uint32 PVP_COMBAT_TIMEOUT = 5 * IN_MILLISECONDS;
+
+    // suppressed combat refs do not generate a combat state for one side of the relation
+    // (used by: vanish, feign death)
+    void SuppressFor(Unit* who);
+    bool IsSuppressedFor(Unit const* who) const { return (who == first) ? _suppressFirst : _suppressSecond; }
+
+private:
+    PvPCombatReference(Unit* first, Unit* second) : CombatReference(first, second, true) { }
+
+    bool Update(uint32 tdiff);
+    void Refresh();
+    void Suppress(Unit* who) { (who == first ? _suppressFirst : _suppressSecond) = true; }
+
+    uint32 _combatTimer = PVP_COMBAT_TIMEOUT;
+    bool _suppressFirst = false;
+    bool _suppressSecond = false;
+
+    friend class CombatManager;
+};
+
+// please check Game/Combat/CombatManager.h for documentation on how this class works!
+class TC_GAME_API CombatManager
+{
+    public:
+        static bool CanBeginCombat(Unit const* a, Unit const* b);
+
+        CombatManager(Unit* owner) : _owner(owner) { }
+        void Update(uint32 tdiff); // called from Unit::Update
+
+        Unit* GetOwner() const { return _owner; }
+        bool HasCombat() const { return HasPvECombat() || HasPvPCombat(); }
+        bool HasPvECombat() const { return !_pveRefs.empty(); }
+        std::unordered_map<ObjectGuid, CombatReference*> const& GetPvECombatRefs() const { return _pveRefs; }
+        bool HasPvPCombat() const;
+        std::unordered_map<ObjectGuid, PvPCombatReference*> const& GetPvPCombatRefs() const { return _pvpRefs; }
+        // If the Unit is in combat, returns an arbitrary Unit that it's in combat with. Otherwise, returns nullptr.
+        Unit* GetAnyTarget() const;
+
+        // return value is the same as calling IsInCombatWith immediately after this returns
+        bool SetInCombatWith(Unit* who);
+        bool IsInCombatWith(ObjectGuid const& who) const;
+        bool IsInCombatWith(Unit const* who) const;
+        void InheritCombatStatesFrom(Unit const* who);
+        void EndCombatBeyondRange(float range, bool includingPvP = false);
+        // flags any pvp refs for suppression on owner's side - these refs will not generate combat until refreshed
+        void SuppressPvPCombat();
+        void EndAllPvECombat();
+        void EndAllPvPCombat();
+        void EndAllCombat() { EndAllPvECombat(); EndAllPvPCombat(); }
+
+        CombatManager(CombatManager const&) = delete;
+        CombatManager& operator=(CombatManager const&) = delete;
+
+    private:
+        static void NotifyAICombat(Unit* me, Unit* other);
+        void PutReference(ObjectGuid const& guid, CombatReference* ref);
+        void PurgeReference(ObjectGuid const& guid, bool pvp);
+        bool UpdateOwnerCombatState() const;
+        Unit* const _owner;
+        std::unordered_map<ObjectGuid, CombatReference*> _pveRefs;
+        std::unordered_map<ObjectGuid, PvPCombatReference*> _pvpRefs;
+
+
+    friend struct CombatReference;
+    friend struct PvPCombatReference;
+};
+
+#endif
diff --git a/src/server/game/Combat/HostileRefManager.cpp b/src/server/game/Combat/HostileRefManager.cpp
deleted file mode 100644
index 503091cf573..00000000000
--- a/src/server/game/Combat/HostileRefManager.cpp
+++ /dev/null
@@ -1,216 +0,0 @@
-/*
- * This file is part of the TrinityCore Project. See AUTHORS file for Copyright information
- *
- * This program is free software; you can redistribute it and/or modify it
- * under the terms of the GNU General Public License as published by the
- * Free Software Foundation; either version 2 of the License, or (at your
- * option) any later version.
- *
- * This program is distributed in the hope that it will be useful, but WITHOUT
- * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
- * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
- * more details.
- *
- * You should have received a copy of the GNU General Public License along
- * with this program. If not, see <http://www.gnu.org/licenses/>.
- */
-
-#include "HostileRefManager.h"
-#include "DB2Structure.h"
-#include "SpellInfo.h"
-#include "ThreatManager.h"
-#include "Unit.h"
-
-HostileRefManager::~HostileRefManager()
-{
-    deleteReferences();
-}
-
-//=================================================
-// send threat to all my haters for the victim
-// The victim is then hated by them as well
-// use for buffs and healing threat functionality
-
-void HostileRefManager::threatAssist(Unit* victim, float baseThreat, SpellInfo const* threatSpell)
-{
-    if (getSize() == 0)
-        return;
-
-    float threat = ThreatCalcHelper::calcThreat(victim, iOwner, baseThreat, (threatSpell ? threatSpell->GetSchoolMask() : SPELL_SCHOOL_MASK_NORMAL), threatSpell);
-    threat /= getSize();
-
-    HostileReference* ref = getFirst();
-    while (ref)
-    {
-        if (ThreatCalcHelper::isValidProcess(victim, ref->GetSource()->GetOwner(), threatSpell))
-            ref->GetSource()->doAddThreat(victim, threat);
-
-        ref = ref->next();
-    }
-}
-
-//=================================================
-
-void HostileRefManager::addTempThreat(float threat, bool apply)
-{
-    HostileReference* ref = getFirst();
-    while (ref)
-    {
-        if (apply)
-        {
-            if (ref->getTempThreatModifier() == 0.0f)
-                ref->addTempThreat(threat);
-        }
-        else
-            ref->resetTempThreat();
-
-        ref = ref->next();
-    }
-}
-
-//=================================================
-
-void HostileRefManager::addThreatPercent(int32 percent)
-{
-    HostileReference* ref = getFirst();
-    while (ref)
-    {
-        ref->addThreatPercent(percent);
-        ref = ref->next();
-    }
-}
-
-//=================================================
-// The online / offline status is given to the method. The calculation has to be done before
-
-void HostileRefManager::setOnlineOfflineState(bool isOnline)
-{
-    HostileReference* ref = getFirst();
-    while (ref)
-    {
-        ref->setOnlineOfflineState(isOnline);
-        ref = ref->next();
-    }
-}
-
-//=================================================
-// The online / offline status is calculated and set
-
-void HostileRefManager::updateThreatTables()
-{
-    HostileReference* ref = getFirst();
-    while (ref)
-    {
-        ref->updateOnlineStatus();
-        ref = ref->next();
-    }
-}
-
-//=================================================
-// The references are not needed anymore
-// tell the source to remove them from the list and free the mem
-
-void HostileRefManager::deleteReferences()
-{
-    HostileReference* ref = getFirst();
-    while (ref)
-    {
-        HostileReference* nextRef = ref->next();
-        ref->removeReference();
-        delete ref;
-        ref = nextRef;
-    }
-}
-
-//=================================================
-// delete one reference, defined by faction
-
-void HostileRefManager::deleteReferencesForFaction(uint32 faction)
-{
-    HostileReference* ref = getFirst();
-    while (ref)
-    {
-        HostileReference* nextRef = ref->next();
-        if (ref->GetSource()->GetOwner()->GetFactionTemplateEntry()->Faction == faction)
-        {
-            ref->removeReference();
-            delete ref;
-        }
-        ref = nextRef;
-    }
-}
-
-//=================================================
-// delete all references out of specified range
-
-void HostileRefManager::deleteReferencesOutOfRange(float range)
-{
-    HostileReference* ref = getFirst();
-    range = range*range;
-    while (ref)
-    {
-        HostileReference* nextRef = ref->next();
-        Unit* owner = ref->GetSource()->GetOwner();
-        if (!owner->isActiveObject() && owner->GetExactDist2dSq(GetOwner()) > range)
-        {
-            ref->removeReference();
-            delete ref;
-        }
-        ref = nextRef;
-    }
-}
-
-//=================================================
-// delete one reference, defined by Unit
-
-void HostileRefManager::deleteReference(Unit* creature)
-{
-    HostileReference* ref = getFirst();
-    while (ref)
-    {
-        HostileReference* nextRef = ref->next();
-        if (ref->GetSource()->GetOwner() == creature)
-        {
-            ref->removeReference();
-            delete ref;
-            break;
-        }
-        ref = nextRef;
-    }
-}
-
-//=================================================
-// set state for one reference, defined by Unit
-
-void HostileRefManager::setOnlineOfflineState(Unit* creature, bool isOnline)
-{
-    HostileReference* ref = getFirst();
-    while (ref)
-    {
-        HostileReference* nextRef = ref->next();
-        if (ref->GetSource()->GetOwner() == creature)
-        {
-            ref->setOnlineOfflineState(isOnline);
-            break;
-        }
-        ref = nextRef;
-    }
-}
-
-//=================================================
-
-void HostileRefManager::UpdateVisibility()
-{
-    HostileReference* ref = getFirst();
-    while (ref)
-    {
-        HostileReference* nextRef = ref->next();
-        if (!ref->GetSource()->GetOwner()->CanSeeOrDetect(GetOwner()))
-        {
-            nextRef = ref->next();
-            ref->removeReference();
-            delete ref;
-        }
-        ref = nextRef;
-    }
-}
diff --git a/src/server/game/Combat/HostileRefManager.h b/src/server/game/Combat/HostileRefManager.h
deleted file mode 100644
index 36d4c82b2fc..00000000000
--- a/src/server/game/Combat/HostileRefManager.h
+++ /dev/null
@@ -1,76 +0,0 @@
-/*
- * This file is part of the TrinityCore Project. See AUTHORS file for Copyright information
- *
- * This program is free software; you can redistribute it and/or modify it
- * under the terms of the GNU General Public License as published by the
- * Free Software Foundation; either version 2 of the License, or (at your
- * option) any later version.
- *
- * This program is distributed in the hope that it will be useful, but WITHOUT
- * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
- * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
- * more details.
- *
- * You should have received a copy of the GNU General Public License along
- * with this program. If not, see <http://www.gnu.org/licenses/>.
- */
-
-#ifndef _HOSTILEREFMANAGER
-#define _HOSTILEREFMANAGER
-
-#include "Common.h"
-#include "RefManager.h"
-
-class Unit;
-class ThreatManager;
-class HostileReference;
-class SpellInfo;
-
-//=================================================
-
-class TC_GAME_API HostileRefManager : public RefManager<Unit, ThreatManager>
-{
-    public:
-        explicit HostileRefManager(Unit* owner) : iOwner(owner) { }
-        ~HostileRefManager();
-
-        Unit* GetOwner() const { return iOwner; }
-
-        // send threat to all my hateres for the victim
-        // The victim is hated than by them as well
-        // use for buffs and healing threat functionality
-        void threatAssist(Unit* victim, float baseThreat, SpellInfo const* threatSpell = nullptr);
-
-        void addTempThreat(float threat, bool apply);
-
-        void addThreatPercent(int32 percent);
-
-        // The references are not needed anymore
-        // tell the source to remove them from the list and free the mem
-        void deleteReferences();
-
-        // Remove specific faction references
-        void deleteReferencesForFaction(uint32 faction);
-
-        // for combat bugs
-        void deleteReferencesOutOfRange(float range);
-
-        HostileReference* getFirst() { return ((HostileReference*) RefManager<Unit, ThreatManager>::getFirst()); }
-
-        void updateThreatTables();
-
-        void setOnlineOfflineState(bool isOnline);
-
-        // set state for one reference, defined by Unit
-        void setOnlineOfflineState(Unit* creature, bool isOnline);
-
-        // delete one reference, defined by Unit
-        void deleteReference(Unit* creature);
-
-        void UpdateVisibility();
-
-    private:
-        Unit* iOwner;
-};
-//=================================================
-#endif
diff --git a/src/server/game/Combat/ThreatManager.cpp b/src/server/game/Combat/ThreatManager.cpp
index e3d5f054abb..16511b14a3b 100644
--- a/src/server/game/Combat/ThreatManager.cpp
+++ b/src/server/game/Combat/ThreatManager.cpp
@@ -16,623 +16,728 @@
  */
 
 #include "ThreatManager.h"
-#include "Unit.h"
 #include "Creature.h"
-#include "Map.h"
-#include "Player.h"
+#include "CombatPackets.h"
+#include "CreatureAI.h"
+#include "MotionMaster.h"
 #include "ObjectAccessor.h"
-#include "UnitEvents.h"
-#include "SpellAuras.h"
+#include "Player.h"
+#include "SpellAuraEffects.h"
 #include "SpellMgr.h"
-#include "TemporarySummon.h"
-
-//==============================================================
-//================= ThreatCalcHelper ===========================
-//==============================================================
-
-// The hatingUnit is not used yet
-float ThreatCalcHelper::calcThreat(Unit* hatedUnit, Unit* /*hatingUnit*/, float threat, SpellSchoolMask schoolMask, SpellInfo const* threatSpell /*= nullptr*/)
-{
-    if (threatSpell)
-    {
-        if (SpellThreatEntry const*  threatEntry = sSpellMgr->GetSpellThreatEntry(threatSpell->Id))
-            if (threatEntry->pctMod != 1.0f)
-                threat *= threatEntry->pctMod;
 
-        // Energize is not affected by Mods
-        for (SpellEffectInfo const* effect : threatSpell->GetEffects())
-            if (effect && (effect->Effect == SPELL_EFFECT_ENERGIZE || effect->ApplyAuraName == SPELL_AURA_PERIODIC_ENERGIZE))
-                return threat;
+#include "Hacks/boost_1_74_fibonacci_heap.h"
+BOOST_1_74_FIBONACCI_HEAP_MSVC_COMPILE_FIX(ThreatManager::threat_list_heap::value_type)
 
-        if (Player* modOwner = hatedUnit->GetSpellModOwner())
-            modOwner->ApplySpellMod(threatSpell, SpellModOp::Hate, threat);
-    }
+const CompareThreatLessThan ThreatManager::CompareThreat;
 
-    return hatedUnit->ApplyTotalThreatModifier(threat, schoolMask);
+void ThreatReference::AddThreat(float amount)
+{
+    if (amount == 0.0f)
+        return;
+    _baseAmount = std::max<float>(_baseAmount + amount, 0.0f);
+    if (amount > 0.0f)
+        HeapNotifyIncreased();
+    else
+        HeapNotifyDecreased();
 }
 
-bool ThreatCalcHelper::isValidProcess(Unit* hatedUnit, Unit* hatingUnit, SpellInfo const* threatSpell /*= nullptr*/)
+void ThreatReference::ScaleThreat(float factor)
 {
-    //function deals with adding threat and adding players and pets into ThreatList
-    //mobs, NPCs, guards have ThreatList and HateOfflineList
-    //players and pets have only InHateListOf
-    //HateOfflineList is used co contain unattackable victims (in-flight, in-water, GM etc.)
-
-    if (!hatedUnit || !hatingUnit)
-        return false;
-
-    // not to self
-    if (hatedUnit == hatingUnit)
-        return false;
-
-    // not to GM
-    if (hatedUnit->GetTypeId() == TYPEID_PLAYER && hatedUnit->ToPlayer()->IsGameMaster())
-        return false;
-
-    // not to dead and not for dead
-    if (!hatedUnit->IsAlive() || !hatingUnit->IsAlive())
-        return false;
-
-    // not in same map or phase
-    if (!hatedUnit->IsInMap(hatingUnit) || !hatedUnit->IsInPhase(hatingUnit))
-        return false;
-
-    // spell not causing threat
-    if (threatSpell && threatSpell->HasAttribute(SPELL_ATTR1_NO_THREAT))
-        return false;
+    if (factor == 1.0f)
+        return;
+    _baseAmount *= factor;
+    if (factor > 1.0f)
+        HeapNotifyIncreased();
+    else
+        HeapNotifyDecreased();
+}
 
-    ASSERT(hatingUnit->GetTypeId() == TYPEID_UNIT);
+void ThreatReference::UpdateOnlineState()
+{
+    OnlineState onlineState = SelectOnlineState();
+    if (onlineState == _online)
+        return;
+    bool increase = (onlineState > _online);
+    _online = onlineState;
+    if (increase)
+        HeapNotifyIncreased();
+    else
+        HeapNotifyDecreased();
 
-    return true;
+    if (!IsAvailable())
+        _owner->GetThreatManager().SendRemoveToClients(_victim);
 }
 
-//============================================================
-//================= HostileReference ==========================
-//============================================================
-
-HostileReference::HostileReference(Unit* refUnit, ThreatManager* threatManager, float threat)
+/*static*/ bool ThreatReference::FlagsAllowFighting(Unit const* a, Unit const* b)
 {
-    iThreat = threat;
-    iTempThreatModifier = 0.0f;
-    link(refUnit, threatManager);
-    iUnitGuid = refUnit->GetGUID();
-    iOnline = true;
-    iAccessible = true;
+    if (a->GetTypeId() == TYPEID_UNIT && a->ToCreature()->IsTrigger())
+        return false;
+    if (a->HasUnitFlag(UNIT_FLAG_PVP_ATTACKABLE))
+    {
+        if (b->HasUnitFlag(UNIT_FLAG_IMMUNE_TO_PC))
+            return false;
+    }
+    else
+    {
+        if (b->HasUnitFlag(UNIT_FLAG_IMMUNE_TO_NPC))
+            return false;
+    }
+    return true;
 }
 
-//============================================================
-// Tell our refTo (target) object that we have a link
-void HostileReference::targetObjectBuildLink()
+ThreatReference::OnlineState ThreatReference::SelectOnlineState()
 {
-    getTarget()->addHatedBy(this);
+    // first, check all offline conditions
+    if (!_owner->CanSeeOrDetect(_victim)) // not in map/phase, or stealth/invis
+        return ONLINE_STATE_OFFLINE;
+    if (_victim->HasUnitState(UNIT_STATE_DIED)) // feign death
+        return ONLINE_STATE_OFFLINE;
+    if (!FlagsAllowFighting(_owner, _victim) || !FlagsAllowFighting(_victim, _owner))
+        return ONLINE_STATE_OFFLINE;
+    // next, check suppression (immunity to chosen melee attack school)
+    if (_victim->IsImmunedToDamage(_owner->GetMeleeDamageSchoolMask()))
+        return ONLINE_STATE_SUPPRESSED;
+    // or any form of CC that will break on damage - disorient, polymorph, blind etc
+    if (_victim->HasBreakableByDamageCrowdControlAura())
+        return ONLINE_STATE_SUPPRESSED;
+    // no suppression - we're online
+    return ONLINE_STATE_ONLINE;
 }
 
-//============================================================
-// Tell our refTo (taget) object, that the link is cut
-void HostileReference::targetObjectDestroyLink()
+void ThreatReference::UpdateTauntState(bool victimIsTaunting)
 {
-    getTarget()->removeHatedBy(this);
-}
+    if (victimIsTaunting)
+    {
+        _taunted = TAUNT_STATE_TAUNT;
+        HeapNotifyIncreased();
+        return;
+    }
 
-//============================================================
-// Tell our refFrom (source) object, that the link is cut (Target destroyed)
+    // Check for SPELL_AURA_MOD_DETAUNT (applied from owner to victim)
+    for (AuraEffect const* eff : _victim->GetAuraEffectsByType(SPELL_AURA_MOD_DETAUNT))
+        if (eff->GetCasterGUID() == _owner->GetGUID())
+        {
+            _taunted = TAUNT_STATE_DETAUNT;
+            HeapNotifyDecreased();
+            return;
+        }
 
-void HostileReference::sourceObjectDestroyLink()
-{
-    setOnlineOfflineState(false);
+    _taunted = TAUNT_STATE_NONE;
+    HeapNotifyChanged();
 }
 
-//============================================================
-// Inform the source, that the status of the reference changed
-
-void HostileReference::fireStatusChanged(ThreatRefStatusChangeEvent& threatRefStatusChangeEvent)
+void ThreatReference::ClearThreat(bool sendRemove)
 {
-    if (GetSource())
-        GetSource()->processThreatEvent(&threatRefStatusChangeEvent);
+    _owner->GetThreatManager().PurgeThreatListRef(_victim->GetGUID(), sendRemove);
+    _victim->GetThreatManager().PurgeThreatenedByMeRef(_owner->GetGUID());
+    delete this;
 }
 
-// -- compatibility layer for combat rewrite (PR #19930)
-Unit* HostileReference::GetOwner() const { return GetSource()->GetOwner(); }
-
-//============================================================
-
-void HostileReference::addThreat(float modThreat)
+/*static*/ bool ThreatManager::CanHaveThreatList(Unit const* who)
 {
-    if (!modThreat)
-        return;
-
-    iThreat += modThreat;
+    // only creatures can have threat list
+    if (who->GetTypeId() != TYPEID_UNIT)
+        return false;
 
-    // the threat is changed. Source and target unit have to be available
-    // if the link was cut before relink it again
-    if (!isOnline())
-        updateOnlineStatus();
+    // pets and totems cannot have threat list
+    if (who->IsPet() || who->IsTotem())
+        return false;
 
-    ThreatRefStatusChangeEvent event(UEV_THREAT_REF_THREAT_CHANGE, this, modThreat);
-    fireStatusChanged(event);
+    // summons cannot have a threat list, unless they are controlled by a creature
+    if (who->HasUnitTypeMask(UNIT_MASK_MINION | UNIT_MASK_GUARDIAN) && !who->GetOwnerGUID().IsCreature())
+        return false;
 
-    if (isValid() && modThreat > 0.0f)
-    {
-        Unit* victimOwner = getTarget()->GetCharmerOrOwner();
-        if (victimOwner && victimOwner->IsAlive())
-            GetSource()->addThreat(victimOwner, 0.0f);     // create a threat to the owner of a pet, if the pet attacks
-    }
+    return true;
 }
 
-void HostileReference::addThreatPercent(int32 percent)
+ThreatManager::ThreatManager(Unit* owner) : _owner(owner), _ownerCanHaveThreatList(false), _ownerEngaged(false), _updateClientTimer(CLIENT_THREAT_UPDATE_INTERVAL), _currentVictimRef(nullptr)
 {
-    addThreat(CalculatePct(iThreat, percent));
+    for (int8 i = 0; i < MAX_SPELL_SCHOOL; ++i)
+        _singleSchoolModifiers[i] = 1.0f;
 }
 
-//============================================================
-// check, if source can reach target and set the status
-
-void HostileReference::updateOnlineStatus()
+void ThreatManager::Initialize()
 {
-    bool online = false;
-    bool accessible = false;
-
-    if (!isValid())
-        if (Unit* target = ObjectAccessor::GetUnit(*GetSourceUnit(), getUnitGuid()))
-            link(target, GetSource());
+    _ownerCanHaveThreatList = ThreatManager::CanHaveThreatList(_owner);
+}
 
-    // only check for online status if
-    // ref is valid
-    // target is no player or not gamemaster
-    // target is not in flight
-    if (isValid()
-        && (getTarget()->GetTypeId() != TYPEID_PLAYER || !getTarget()->ToPlayer()->IsGameMaster())
-        && !getTarget()->HasUnitState(UNIT_STATE_IN_FLIGHT)
-        && getTarget()->IsInMap(GetSourceUnit())
-        && getTarget()->IsInPhase(GetSourceUnit())
-        )
+void ThreatManager::Update(uint32 tdiff)
+{
+    if (_updateClientTimer <= tdiff)
     {
-        Creature* creature = GetSourceUnit()->ToCreature();
-        online = getTarget()->isInAccessiblePlaceFor(creature);
-        if (!online)
-        {
-            if (creature->IsWithinCombatRange(getTarget(), creature->m_CombatDistance))
-                online = true;                              // not accessible but stays online
-        }
-        else
-            accessible = true;
+        _updateClientTimer = CLIENT_THREAT_UPDATE_INTERVAL;
+        SendThreatListToClients();
     }
-
-    setAccessibleState(accessible);
-    setOnlineOfflineState(online);
+    else
+        _updateClientTimer -= tdiff;
 }
 
-//============================================================
-// set the status and fire the event on status change
-
-void HostileReference::setOnlineOfflineState(bool isOnline)
+Unit* ThreatManager::GetCurrentVictim() const
 {
-    if (iOnline != isOnline)
-    {
-        iOnline = isOnline;
-        if (!iOnline)
-            setAccessibleState(false);                      // if not online that not accessable as well
-
-        ThreatRefStatusChangeEvent event(UEV_THREAT_REF_ONLINE_STATUS, this);
-        fireStatusChanged(event);
-    }
+    if (_currentVictimRef)
+        return _currentVictimRef->GetVictim();
+    return nullptr;
 }
 
-//============================================================
+Unit* ThreatManager::GetAnyTarget() const
+{
+    for (ThreatReference const* ref : _sortedThreatList)
+        if (!ref->IsOffline())
+            return ref->GetVictim();
+    return nullptr;
+}
 
-void HostileReference::setAccessibleState(bool isAccessible)
+Unit* ThreatManager::SelectVictim()
 {
-    if (iAccessible != isAccessible)
+    if (_sortedThreatList.empty())
+        return nullptr;
+
+    ThreatReference const* newVictimRef = ReselectVictim();
+    if (newVictimRef != _currentVictimRef)
     {
-        iAccessible = isAccessible;
+        if (newVictimRef)
+            SendNewVictimToClients(newVictimRef);
 
-        ThreatRefStatusChangeEvent event(UEV_THREAT_REF_ACCESSIBLE_STATUS, this);
-        fireStatusChanged(event);
+        _currentVictimRef = newVictimRef;
     }
+    return newVictimRef ? newVictimRef->GetVictim() : nullptr;
 }
 
-//============================================================
-// prepare the reference for deleting
-// this is called be the target
-
-void HostileReference::removeReference()
+bool ThreatManager::IsThreatListEmpty(bool includeOffline) const
 {
-    invalidate();
-
-    ThreatRefStatusChangeEvent event(UEV_THREAT_REF_REMOVE_FROM_LIST, this);
-    fireStatusChanged(event);
+    if (includeOffline)
+        return _sortedThreatList.empty();
+    for (ThreatReference const* ref : _sortedThreatList)
+        if (ref->IsAvailable())
+            return false;
+    return true;
 }
 
-//============================================================
-
-Unit* HostileReference::GetSourceUnit()
+bool ThreatManager::IsThreatenedBy(ObjectGuid const& who, bool includeOffline) const
 {
-    return (GetSource()->GetOwner());
+    auto it = _myThreatListEntries.find(who);
+    if (it == _myThreatListEntries.end())
+        return false;
+    return (includeOffline || it->second->IsAvailable());
 }
+bool ThreatManager::IsThreatenedBy(Unit const* who, bool includeOffline) const { return IsThreatenedBy(who->GetGUID(), includeOffline); }
 
-//============================================================
-//================ ThreatContainer ===========================
-//============================================================
-
-void ThreatContainer::clearReferences()
+float ThreatManager::GetThreat(Unit const* who, bool includeOffline) const
 {
-    for (ThreatContainer::StorageType::const_iterator i = iThreatList.begin(); i != iThreatList.end(); ++i)
-    {
-        (*i)->unlink();
-        delete (*i);
-    }
-
-    iThreatList.clear();
+    auto it = _myThreatListEntries.find(who->GetGUID());
+    if (it == _myThreatListEntries.end())
+        return 0.0f;
+    return (includeOffline || it->second->IsAvailable()) ? it->second->GetThreat() : 0.0f;
 }
 
-//============================================================
-// Return the HostileReference of NULL, if not found
-HostileReference* ThreatContainer::getReferenceByTarget(Unit const* victim) const
+std::vector<ThreatReference*> ThreatManager::GetModifiableThreatList() const
 {
-    if (!victim)
-        return nullptr;
-
-    ObjectGuid guid = victim->GetGUID();
-    for (ThreatContainer::StorageType::const_iterator i = iThreatList.begin(); i != iThreatList.end(); ++i)
-    {
-        HostileReference* ref = (*i);
-        if (ref && ref->getUnitGuid() == guid)
-            return ref;
-    }
-
-    return nullptr;
+    std::vector<ThreatReference*> list;
+    list.reserve(_myThreatListEntries.size());
+    for (auto it = _sortedThreatList.ordered_begin(), end = _sortedThreatList.ordered_end(); it != end; ++it)
+        list.push_back(const_cast<ThreatReference*>(*it));
+    return list;
 }
 
-//============================================================
-// Add the threat, if we find the reference
-
-HostileReference* ThreatContainer::addThreat(Unit* victim, float threat)
+bool ThreatManager::IsThreateningAnyone(bool includeOffline) const
 {
-    HostileReference* ref = getReferenceByTarget(victim);
-    if (ref)
-        ref->addThreat(threat);
-    return ref;
+    if (includeOffline)
+        return !_threatenedByMe.empty();
+    for (auto const& pair : _threatenedByMe)
+        if (pair.second->IsAvailable())
+            return true;
+    return false;
 }
 
-//============================================================
-
-void ThreatContainer::ModifyThreatByPercent(Unit* victim, int32 percent)
+bool ThreatManager::IsThreateningTo(ObjectGuid const& who, bool includeOffline) const
 {
-    if (HostileReference* ref = getReferenceByTarget(victim))
-        ref->addThreatPercent(percent);
+    auto it = _threatenedByMe.find(who);
+    if (it == _threatenedByMe.end())
+        return false;
+    return (includeOffline || it->second->IsAvailable());
 }
+bool ThreatManager::IsThreateningTo(Unit const* who, bool includeOffline) const { return IsThreateningTo(who->GetGUID(), includeOffline); }
 
-//============================================================
-// Check if the list is dirty and sort if necessary
-
-void ThreatContainer::update()
+void ThreatManager::UpdateOnlineStates(bool meThreateningOthers, bool othersThreateningMe)
 {
-    if (iDirty && iThreatList.size() > 1)
-        iThreatList.sort(Trinity::ThreatOrderPred());
-
-    iDirty = false;
+    if (othersThreateningMe)
+        for (auto const& pair : _myThreatListEntries)
+            pair.second->UpdateOnlineState();
+    if (meThreateningOthers)
+        for (auto const& pair : _threatenedByMe)
+            pair.second->UpdateOnlineState();
 }
 
-//============================================================
-// return the next best victim
-// could be the current victim
-
-HostileReference* ThreatContainer::selectNextVictim(Creature* attacker, HostileReference* currentVictim) const
+static void SaveCreatureHomePositionIfNeed(Creature* c)
 {
-    HostileReference* currentRef = nullptr;
-    bool found = false;
-    bool noPriorityTargetFound = false;
-
-    ThreatContainer::StorageType::const_iterator lastRef = iThreatList.end();
-    --lastRef;
+    MovementGeneratorType const movetype = c->GetMotionMaster()->GetCurrentMovementGeneratorType();
+    if (movetype == WAYPOINT_MOTION_TYPE || movetype == POINT_MOTION_TYPE || (c->IsAIEnabled && c->AI()->IsEscorted()))
+        c->SetHomePosition(c->GetPosition());
+}
 
-    for (ThreatContainer::StorageType::const_iterator iter = iThreatList.begin(); iter != iThreatList.end() && !found;)
+void ThreatManager::AddThreat(Unit* target, float amount, SpellInfo const* spell, bool ignoreModifiers, bool ignoreRedirects)
+{
+    // step 1: we can shortcut if the spell has one of the NO_THREAT attrs set - nothing will happen
+    if (spell)
     {
-        currentRef = (*iter);
+        if (spell->HasAttribute(SPELL_ATTR1_NO_THREAT))
+            return;
+        if (!_owner->IsEngaged() && spell->HasAttribute(SPELL_ATTR3_NO_INITIAL_AGGRO))
+            return;
+    }
 
-        Unit* target = currentRef->getTarget();
-        ASSERT(target);                                     // if the ref has status online the target must be there !
+    // while riding a vehicle, all threat goes to the vehicle, not the pilot
+    if (Unit* vehicle = target->GetVehicleBase())
+    {
+        AddThreat(vehicle, amount, spell, ignoreModifiers, ignoreRedirects);
+        if (target->HasUnitTypeMask(UNIT_MASK_ACCESSORY)) // accessories are fully treated as components of the parent and cannot have threat
+            return;
+        amount = 0.0f;
+    }
 
-        // some units are prefered in comparison to others
-        if (!noPriorityTargetFound && (target->IsImmunedToDamage(attacker->GetMeleeDamageSchoolMask()) || target->HasNegativeAuraWithInterruptFlag(SpellAuraInterruptFlags::Damage)))
+    // If victim is personal spawn, redirect all aggro to summoner
+    if (target->IsPrivateObject() && (!GetOwner()->IsPrivateObject() || !GetOwner()->CheckPrivateObjectOwnerVisibility(target)))
+    {
+        if (Unit* privateObjectOwner = ObjectAccessor::GetUnit(*GetOwner(), target->GetPrivateObjectOwner()))
         {
-            if (iter != lastRef)
-            {
-                // current victim is a second choice target, so don't compare threat with it below
-                if (currentRef == currentVictim)
-                    currentVictim = nullptr;
-                ++iter;
-                continue;
-            }
-            else
-            {
-                // if we reached to this point, everyone in the threatlist is a second choice target. In such a situation the target with the highest threat should be attacked.
-                noPriorityTargetFound = true;
-                iter = iThreatList.begin();
-                continue;
-            }
+            AddThreat(privateObjectOwner, amount, spell, ignoreModifiers, ignoreRedirects);
+            amount = 0.0f;
         }
+    }
+
+    // if we cannot actually have a threat list, we instead just set combat state and avoid creating threat refs altogether
+    if (!CanHaveThreatList())
+    {
+        CombatManager& combatMgr = _owner->GetCombatManager();
+        if (!combatMgr.SetInCombatWith(target))
+            return;
+        // traverse redirects and put them in combat, too
+        for (auto const& pair : target->GetThreatManager()._redirectInfo)
+            if (!combatMgr.IsInCombatWith(pair.first))
+                if (Unit* redirTarget = ObjectAccessor::GetUnit(*_owner, pair.first))
+                    combatMgr.SetInCombatWith(redirTarget);
+        return;
+    }
 
-        if (attacker->CanCreatureAttack(target))           // skip non attackable currently targets
+    // apply threat modifiers to the amount
+    if (!ignoreModifiers)
+        amount = CalculateModifiedThreat(amount, target, spell);
+
+    // if we're increasing threat, send some/all of it to redirection targets instead if applicable
+    if (!ignoreRedirects && amount > 0.0f)
+    {
+        auto const& redirInfo = target->GetThreatManager()._redirectInfo;
+        if (!redirInfo.empty())
         {
-            if (currentVictim)                              // select 1.3/1.1 better target in comparison current target
+            float const origAmount = amount;
+            for (auto const& pair : redirInfo) // (victim,pct)
             {
-                // list sorted and and we check current target, then this is best case
-                if (currentVictim == currentRef || currentRef->getThreat() <= 1.1f * currentVictim->getThreat())
+                Unit* redirTarget = nullptr;
+                auto it = _myThreatListEntries.find(pair.first); // try to look it up in our threat list first (faster)
+                if (it != _myThreatListEntries.end())
+                    redirTarget = it->second->_victim;
+                else
+                    redirTarget = ObjectAccessor::GetUnit(*_owner, pair.first);
+
+                if (redirTarget)
                 {
-                    if (currentVictim != currentRef && attacker->CanCreatureAttack(currentVictim->getTarget()))
-                        currentRef = currentVictim;            // for second case, if currentvictim is attackable
-
-                    found = true;
-                    break;
-                }
-
-                if (currentRef->getThreat() > 1.3f * currentVictim->getThreat() ||
-                    (currentRef->getThreat() > 1.1f * currentVictim->getThreat() &&
-                    attacker->IsWithinMeleeRange(target)))
-                {                                           //implement 110% threat rule for targets in melee range
-                    found = true;                           //and 130% rule for targets in ranged distances
-                    break;                                  //for selecting alive targets
+                    float amountRedirected = CalculatePct(origAmount, pair.second);
+                    AddThreat(redirTarget, amountRedirected, spell, true, true);
+                    amount -= amountRedirected;
                 }
             }
-            else                                            // select any
-            {
-                found = true;
-                break;
-            }
         }
-        ++iter;
     }
-    if (!found)
-        currentRef = nullptr;
 
-    return currentRef;
-}
+    // ok, now we actually apply threat
+    // check if we already have an entry - if we do, just increase threat for that entry and we're done
+    auto it = _myThreatListEntries.find(target->GetGUID());
+    if (it != _myThreatListEntries.end())
+    {
+        it->second->AddThreat(amount);
+        return;
+    }
 
-//============================================================
-//=================== ThreatManager ==========================
-//============================================================
+    // otherwise, ensure we're in combat (threat implies combat!)
+    if (!_owner->GetCombatManager().SetInCombatWith(target)) // if this returns false, we're not actually in combat, and thus cannot have threat!
+        return;                                              // typical causes: bad scripts trying to add threat to GMs, dead targets etc
 
-ThreatManager::ThreatManager(Unit* owner) : iCurrentVictim(nullptr), iOwner(owner), iUpdateTimer(THREAT_UPDATE_INTERVAL) { }
+    // ok, we're now in combat - create the threat list reference and push it to the respective managers
+    ThreatReference* ref = new ThreatReference(this, target, amount);
+    PutThreatListRef(target->GetGUID(), ref);
+    target->GetThreatManager().PutThreatenedByMeRef(_owner->GetGUID(), ref);
+    if (!ref->IsOffline() && !_ownerEngaged)
+    {
+        _ownerEngaged = true;
+
+        Creature* cOwner = _owner->ToCreature();
+        assert(cOwner); // if we got here the owner can have a threat list, and must be a creature!
+        SaveCreatureHomePositionIfNeed(cOwner);
+        if (cOwner->IsAIEnabled)
+            cOwner->AI()->JustEngagedWith(target);
+    }
+}
 
-// -- compatibility layer for combat rewrite (PR #19930)
-void ThreatManager::ForwardThreatForAssistingMe(Unit* victim, float amount, SpellInfo const* spell, bool ignoreModifiers, bool ignoreRedirection)
+void ThreatManager::ScaleThreat(Unit* target, float factor)
 {
-    (void)ignoreModifiers; (void)ignoreRedirection;
-    GetOwner()->getHostileRefManager().threatAssist(victim, amount, spell);
+    auto it = _myThreatListEntries.find(target->GetGUID());
+    if (it != _myThreatListEntries.end())
+        it->second->ScaleThreat(std::max<float>(factor,0.0f));
 }
 
-void ThreatManager::AddThreat(Unit* victim, float amount, SpellInfo const* spell, bool ignoreModifiers, bool ignoreRedirection)
+void ThreatManager::MatchUnitThreatToHighestThreat(Unit* target)
 {
-    (void)ignoreModifiers; (void)ignoreRedirection;
-    if (!iOwner->CanHaveThreatList() || iOwner->HasUnitState(UNIT_STATE_EVADE))
+    if (_sortedThreatList.empty())
         return;
 
-    if (iOwner->IsControlledByPlayer() || victim->IsControlledByPlayer())
+    auto it = _sortedThreatList.begin(), end = _sortedThreatList.end();
+    ThreatReference const* highest = *it;
+    if (!highest->IsOnline())
+        return;
+
+    if (highest->_taunted) // might need to skip this - new max could be one of the preceding elements (heap property) since there is only one taunt element
     {
-        if (iOwner->IsFriendlyTo(victim) || victim->IsFriendlyTo(iOwner))
-            return;
+        if ((++it) != end)
+        {
+            ThreatReference const* a = *it;
+            if (a->IsOnline() && a->GetThreat() > highest->GetThreat())
+                highest = a;
+
+            if ((++it) != end)
+            {
+                ThreatReference const* a = *it;
+                if (a->IsOnline() && a->GetThreat() > highest->GetThreat())
+                    highest = a;
+            }
+        }
     }
-    else if (!iOwner->IsHostileTo(victim) && !victim->IsHostileTo(iOwner))
-        return;
 
-    iOwner->SetInCombatWith(victim);
-    victim->SetInCombatWith(iOwner);
-    addThreat(victim, amount, spell ? spell->GetSchoolMask() : victim->GetMeleeDamageSchoolMask(), spell);
+    AddThreat(target, highest->GetThreat() - GetThreat(target, true), nullptr, true, true);
 }
 
-void ThreatManager::ClearAllThreat()
+void ThreatManager::TauntUpdate()
 {
-    if (iOwner->CanHaveThreatList(true) && !isThreatListEmpty())
-        iOwner->SendClearThreatListOpcode();
-    clearReferences();
+    std::list<AuraEffect*> const& tauntEffects = _owner->GetAuraEffectsByType(SPELL_AURA_MOD_TAUNT);
+    auto threatEnd = _myThreatListEntries.end();
+    ThreatReference* tauntRef = nullptr;
+    // Only the last taunt effect applied by something still on our threat list is considered
+    for (auto it = tauntEffects.rbegin(), end = tauntEffects.rend(); it != end; ++it)
+    {
+        auto threatIt = _myThreatListEntries.find((*it)->GetCasterGUID());
+        if (threatIt == threatEnd)
+            continue;
+        if (!threatIt->second->IsOnline())
+            continue;
+        tauntRef = threatIt->second;
+        break;
+    }
+    for (auto const& pair : _myThreatListEntries)
+        pair.second->UpdateTauntState(pair.second == tauntRef);
 }
 
-//============================================================
-
-void ThreatManager::clearReferences()
+void ThreatManager::ResetAllThreat()
 {
-    iThreatContainer.clearReferences();
-    iThreatOfflineContainer.clearReferences();
-    iCurrentVictim = nullptr;
-    iUpdateTimer = THREAT_UPDATE_INTERVAL;
+    for (auto const& pair : _myThreatListEntries)
+        pair.second->SetThreat(0.0f);
 }
 
-//============================================================
+void ThreatManager::ClearThreat(Unit* target)
+{
+    auto it = _myThreatListEntries.find(target->GetGUID());
+    if (it != _myThreatListEntries.end())
+        it->second->ClearThreat();
+}
 
-void ThreatManager::addThreat(Unit* victim, float threat, SpellSchoolMask schoolMask, SpellInfo const* threatSpell)
+void ThreatManager::ClearAllThreat()
 {
-    if (!ThreatCalcHelper::isValidProcess(victim, GetOwner(), threatSpell))
+    _ownerEngaged = false;
+    if (_myThreatListEntries.empty())
         return;
 
-    doAddThreat(victim, ThreatCalcHelper::calcThreat(victim, iOwner, threat, schoolMask, threatSpell));
+    SendClearAllThreatToClients();
+    do
+        _myThreatListEntries.begin()->second->ClearThreat(false);
+    while (!_myThreatListEntries.empty());
 }
 
-void ThreatManager::doAddThreat(Unit* victim, float threat)
+ThreatReference const* ThreatManager::ReselectVictim()
 {
-    uint32 redirectThreadPct = victim->GetRedirectThreatPercent();
-    Unit* redirectTarget = victim->GetRedirectThreatTarget();
+    ThreatReference const* oldVictimRef = _currentVictimRef;
+    if (oldVictimRef && !oldVictimRef->IsAvailable())
+        oldVictimRef = nullptr;
+    // in 99% of cases - we won't need to actually look at anything beyond the first element
+    ThreatReference const* highest = _sortedThreatList.top();
+    // if the highest reference is offline, the entire list is offline, and we indicate this
+    if (!highest->IsAvailable())
+        return nullptr;
+    // if we have no old victim, or old victim is still highest, then highest is our target and we're done
+    if (!oldVictimRef || highest == oldVictimRef)
+        return highest;
+    // if highest threat doesn't break 110% of old victim, nothing below it is going to do so either; new victim = old victim and done
+    if (!ThreatManager::CompareReferencesLT(oldVictimRef, highest, 1.1f))
+        return oldVictimRef;
+    // if highest threat breaks 130%, it's our new target regardless of range (and we're done)
+    if (ThreatManager::CompareReferencesLT(oldVictimRef, highest, 1.3f))
+        return highest;
+    // if it doesn't break 130%, we need to check if it's melee - if yes, it breaks 110% (we checked earlier) and is our new target
+    if (_owner->IsWithinMeleeRange(highest->_victim))
+        return highest;
+    // If we get here, highest threat is ranged, but below 130% of current - there might be a melee that breaks 110% below us somewhere, so now we need to actually look at the next highest element
+    // luckily, this is a heap, so getting the next highest element is O(log n), and we're just gonna do that repeatedly until we've seen enough targets (or find a target)
+    auto it = _sortedThreatList.ordered_begin(), end = _sortedThreatList.ordered_end();
+    while (it != end)
+    {
+        ThreatReference const* next = *it;
+        // if we've found current victim, we're done (nothing above is higher, and nothing below can be higher)
+        if (next == oldVictimRef)
+            return next;
+        // if next isn't above 110% threat, then nothing below it can be either - we're done, old victim stays
+        if (!ThreatManager::CompareReferencesLT(oldVictimRef, next, 1.1f))
+            return oldVictimRef;
+        // if next is melee, he's above 110% and our new victim
+        if (_owner->IsWithinMeleeRange(next->_victim))
+            return next;
+        // otherwise the next highest target may still be a melee above 110% and we need to look further
+        ++it;
+    }
+    // we should have found the old victim at some point in the loop above, so execution should never get to this point
+    ASSERT(false && "Current victim not found in sorted threat list even though it has a reference - manager desync!");
+    return nullptr;
+}
 
-    // If victim is personal spawn, redirect all aggro to summoner
-    if (victim->IsPrivateObject() && (!GetOwner()->IsPrivateObject() || !GetOwner()->CheckPrivateObjectOwnerVisibility(victim)))
+// returns true if a is LOWER on the threat list than b
+/*static*/ bool ThreatManager::CompareReferencesLT(ThreatReference const* a, ThreatReference const* b, float aWeight)
+{
+    if (a->_online != b->_online) // online state precedence (ONLINE > SUPPRESSED > OFFLINE)
+        return a->_online < b->_online;
+    if (a->_taunted != b->_taunted) // taunt state precedence (TAUNT > NONE > DETAUNT)
+        return a->_taunted < b->_taunted;
+    return (a->GetThreat()*aWeight < b->GetThreat());
+}
+
+/*static*/ float ThreatManager::CalculateModifiedThreat(float threat, Unit const* victim, SpellInfo const* spell)
+{
+    // modifiers by spell
+    if (spell)
     {
-        redirectThreadPct = 100;
-        redirectTarget = ObjectAccessor::GetUnit(*GetOwner(), victim->GetPrivateObjectOwner());
+        if (SpellThreatEntry const* threatEntry = sSpellMgr->GetSpellThreatEntry(spell->Id))
+            if (threatEntry->pctMod != 1.0f) // flat/AP modifiers handled in Spell::HandleThreatSpells
+                threat *= threatEntry->pctMod;
+
+        if (Player* modOwner = victim->GetSpellModOwner())
+            modOwner->ApplySpellMod(spell, SpellModOp::Hate, threat);
     }
 
-    // must check > 0.0f, otherwise dead loop
-    if (threat > 0.0f && redirectThreadPct)
+    // modifiers by effect school
+    ThreatManager const& victimMgr = victim->GetThreatManager();
+    SpellSchoolMask const mask = spell ? spell->GetSchoolMask() : SPELL_SCHOOL_MASK_NORMAL;
+    switch (mask)
     {
-        if (redirectTarget)
+        case SPELL_SCHOOL_MASK_NORMAL:
+            threat *= victimMgr._singleSchoolModifiers[SPELL_SCHOOL_NORMAL];
+            break;
+        case SPELL_SCHOOL_MASK_HOLY:
+            threat *= victimMgr._singleSchoolModifiers[SPELL_SCHOOL_HOLY];
+            break;
+        case SPELL_SCHOOL_MASK_FIRE:
+            threat *= victimMgr._singleSchoolModifiers[SPELL_SCHOOL_FIRE];
+            break;
+        case SPELL_SCHOOL_MASK_NATURE:
+            threat *= victimMgr._singleSchoolModifiers[SPELL_SCHOOL_NATURE];
+            break;
+        case SPELL_SCHOOL_MASK_FROST:
+            threat *= victimMgr._singleSchoolModifiers[SPELL_SCHOOL_FROST];
+            break;
+        case SPELL_SCHOOL_MASK_SHADOW:
+            threat *= victimMgr._singleSchoolModifiers[SPELL_SCHOOL_SHADOW];
+            break;
+        case SPELL_SCHOOL_MASK_ARCANE:
+            threat *= victimMgr._singleSchoolModifiers[SPELL_SCHOOL_ARCANE];
+            break;
+        default:
         {
-            float redirectThreat = CalculatePct(threat, redirectThreadPct);
-            threat -= redirectThreat;
-            if (ThreatCalcHelper::isValidProcess(redirectTarget, GetOwner()))
-                _addThreat(redirectTarget, redirectThreat);
+            auto it = victimMgr._multiSchoolModifiers.find(mask);
+            if (it != victimMgr._multiSchoolModifiers.end())
+            {
+                threat *= it->second;
+                break;
+            }
+            float mod = victim->GetTotalAuraMultiplierByMiscMask(SPELL_AURA_MOD_THREAT, mask);
+            victimMgr._multiSchoolModifiers[mask] = mod;
+            threat *= mod;
+            break;
         }
     }
-
-    _addThreat(victim, threat);
+    return threat;
 }
 
-void ThreatManager::_addThreat(Unit* victim, float threat)
+void ThreatManager::SendClearAllThreatToClients() const
 {
-    HostileReference* ref = iThreatContainer.addThreat(victim, threat);
-    // Ref is not in the online refs, search the offline refs next
-    if (!ref)
-        ref = iThreatOfflineContainer.addThreat(victim, threat);
+    WorldPackets::Combat::ThreatClear threatClear;
+    threatClear.UnitGUID = _owner->GetGUID();
+    _owner->SendMessageToSet(threatClear.Write(), false);
+}
 
-    if (!ref) // there was no ref => create a new one
+void ThreatManager::SendThreatListToClients() const
+{
+    WorldPackets::Combat::ThreatUpdate threatUpdate;
+    threatUpdate.UnitGUID = _owner->GetGUID();
+    threatUpdate.ThreatList.reserve(_sortedThreatList.size());
+    for (ThreatReference const* ref : _sortedThreatList)
     {
-        bool isFirst = iThreatContainer.empty();
-                                                            // threat has to be 0 here
-        HostileReference* hostileRef = new HostileReference(victim, this, 0);
-        iThreatContainer.addReference(hostileRef);
-        hostileRef->addThreat(threat); // now we add the real threat
-        if (victim->GetTypeId() == TYPEID_PLAYER && victim->ToPlayer()->IsGameMaster())
-            hostileRef->setOnlineOfflineState(false); // GM is always offline
-        else if (isFirst)
-            setCurrentVictim(hostileRef);
+        if (!ref->IsAvailable()) // @todo check if suppressed threat should get sent for bubble/iceblock/hop etc
+            continue;
+
+        WorldPackets::Combat::ThreatInfo threatInfo;
+        threatInfo.UnitGUID = ref->GetVictim()->GetGUID();
+        threatInfo.Threat = int64(ref->GetThreat() * 100);
+        threatUpdate.ThreatList.push_back(threatInfo);
     }
+    _owner->SendMessageToSet(threatUpdate.Write(), false);
 }
 
-//============================================================
-
-void ThreatManager::ModifyThreatByPercent(Unit* victim, int32 percent)
+void ThreatManager::ForwardThreatForAssistingMe(Unit* assistant, float baseAmount, SpellInfo const* spell, bool ignoreModifiers)
 {
-    iThreatContainer.ModifyThreatByPercent(victim, percent);
+    if (spell && spell->HasAttribute(SPELL_ATTR1_NO_THREAT)) // shortcut, none of the calls would do anything
+        return;
+    for (auto const& pair : _threatenedByMe)
+        pair.second->GetOwner()->GetThreatManager().AddThreat(assistant, baseAmount, spell, ignoreModifiers);
 }
 
-//============================================================
-
-Unit* ThreatManager::getHostilTarget()
+void ThreatManager::RemoveMeFromThreatLists()
 {
-    iThreatContainer.update();
-    HostileReference* nextVictim = iThreatContainer.selectNextVictim(GetOwner()->ToCreature(), getCurrentVictim());
-    setCurrentVictim(nextVictim);
-    return getCurrentVictim() != nullptr ? getCurrentVictim()->getTarget() : nullptr;
+    while (!_threatenedByMe.empty())
+        _threatenedByMe.begin()->second->ClearThreat();
 }
 
-//============================================================
-
-float ThreatManager::getThreat(Unit* victim, bool alsoSearchOfflineList)
+void ThreatManager::UpdateMyTempModifiers()
 {
-    float threat = 0.0f;
-    HostileReference* ref = iThreatContainer.getReferenceByTarget(victim);
-    if (!ref && alsoSearchOfflineList)
-        ref = iThreatOfflineContainer.getReferenceByTarget(victim);
-    if (ref)
-        threat = ref->getThreat();
-    return threat;
+    int32 mod = 0;
+    for (AuraEffect const* eff : _owner->GetAuraEffectsByType(SPELL_AURA_MOD_TOTAL_THREAT))
+        mod += eff->GetAmount();
+
+    for (auto const& pair : _threatenedByMe)
+    {
+        pair.second->_tempModifier = mod;
+        pair.second->HeapNotifyChanged();
+    }
 }
 
-//============================================================
+void ThreatManager::UpdateMySpellSchoolModifiers()
+{
+    for (uint8 i = 0; i < MAX_SPELL_SCHOOL; ++i)
+        _singleSchoolModifiers[i] = _owner->GetTotalAuraMultiplierByMiscMask(SPELL_AURA_MOD_THREAT, 1 << i);
+    _multiSchoolModifiers.clear();
+}
 
-void ThreatManager::tauntApply(Unit* taunter)
+void ThreatManager::RegisterRedirectThreat(uint32 spellId, ObjectGuid const& victim, uint32 pct)
 {
-    HostileReference* ref = iThreatContainer.getReferenceByTarget(taunter);
-    if (getCurrentVictim() && ref && (ref->getThreat() < getCurrentVictim()->getThreat()))
-    {
-        if (ref->getTempThreatModifier() == 0.0f) // Ok, temp threat is unused
-            ref->setTempThreat(getCurrentVictim()->getThreat());
-    }
+    _redirectRegistry[spellId][victim] = pct;
+    UpdateRedirectInfo();
 }
 
-//============================================================
+void ThreatManager::UnregisterRedirectThreat(uint32 spellId)
+{
+    auto it = _redirectRegistry.find(spellId);
+    if (it == _redirectRegistry.end())
+        return;
+    _redirectRegistry.erase(it);
+    UpdateRedirectInfo();
+}
 
-void ThreatManager::tauntFadeOut(Unit* taunter)
+void ThreatManager::UnregisterRedirectThreat(uint32 spellId, ObjectGuid const& victim)
 {
-    HostileReference* ref = iThreatContainer.getReferenceByTarget(taunter);
-    if (ref)
-        ref->resetTempThreat();
+    auto it = _redirectRegistry.find(spellId);
+    if (it == _redirectRegistry.end())
+        return;
+    auto& victimMap = it->second;
+    auto it2 = victimMap.find(victim);
+    if (it2 == victimMap.end())
+        return;
+    victimMap.erase(it2);
+    UpdateRedirectInfo();
 }
 
-//============================================================
+void ThreatManager::SendRemoveToClients(Unit const* victim) const
+{
+    WorldPackets::Combat::ThreatRemove threatRemove;
+    threatRemove.UnitGUID = _owner->GetGUID();
+    threatRemove.AboutGUID = victim->GetGUID();
+    _owner->SendMessageToSet(threatRemove.Write(), false);
+}
 
-void ThreatManager::setCurrentVictim(HostileReference* pHostileReference)
+void ThreatManager::SendNewVictimToClients(ThreatReference const* victimRef) const
 {
-    if (pHostileReference && pHostileReference != iCurrentVictim)
+    WorldPackets::Combat::HighestThreatUpdate highestThreatUpdate;
+    highestThreatUpdate.UnitGUID = _owner->GetGUID();
+    highestThreatUpdate.HighestThreatGUID = victimRef->_victim->GetGUID();
+    highestThreatUpdate.ThreatList.reserve(_sortedThreatList.size());
+    for (ThreatReference const* ref : _sortedThreatList)
     {
-        iOwner->SendChangeCurrentVictimOpcode(pHostileReference);
+        if (!ref->IsAvailable())
+            continue;
+
+        WorldPackets::Combat::ThreatInfo threatInfo;
+        threatInfo.UnitGUID = ref->GetVictim()->GetGUID();
+        threatInfo.Threat = int64(ref->GetThreat() * 100);
+        highestThreatUpdate.ThreatList.push_back(threatInfo);
     }
-    iCurrentVictim = pHostileReference;
+    _owner->SendMessageToSet(highestThreatUpdate.Write(), false);
 }
 
-//============================================================
-// The hated unit is gone, dead or deleted
-// return true, if the event is consumed
+void ThreatManager::PutThreatListRef(ObjectGuid const& guid, ThreatReference* ref)
+{
+    auto& inMap = _myThreatListEntries[guid];
+    ASSERT(!inMap && "Duplicate threat list entry being inserted - memory leak!");
+    inMap = ref;
+    ref->_handle = _sortedThreatList.push(ref);
+}
 
-void ThreatManager::processThreatEvent(ThreatRefStatusChangeEvent* threatRefStatusChangeEvent)
+void ThreatManager::PurgeThreatListRef(ObjectGuid const& guid, bool sendRemove)
 {
-    threatRefStatusChangeEvent->setThreatManager(this);     // now we can set the threat manager
+    auto it = _myThreatListEntries.find(guid);
+    if (it == _myThreatListEntries.end())
+        return;
+    ThreatReference* ref = it->second;
+    _myThreatListEntries.erase(it);
 
-    HostileReference* hostilRef = threatRefStatusChangeEvent->getReference();
+    if (_currentVictimRef == ref)
+        _currentVictimRef = nullptr;
 
-    switch (threatRefStatusChangeEvent->getType())
-    {
-        case UEV_THREAT_REF_THREAT_CHANGE:
-            if ((getCurrentVictim() == hostilRef && threatRefStatusChangeEvent->getFValue()<0.0f) ||
-                (getCurrentVictim() != hostilRef && threatRefStatusChangeEvent->getFValue()>0.0f))
-                setDirty(true);                             // the order in the threat list might have changed
-            break;
-        case UEV_THREAT_REF_ONLINE_STATUS:
-            if (!hostilRef->isOnline())
-            {
-                if (hostilRef == getCurrentVictim())
-                {
-                    setCurrentVictim(nullptr);
-                    setDirty(true);
-                }
-                iOwner->SendRemoveFromThreatListOpcode(hostilRef);
-                iThreatContainer.remove(hostilRef);
-                iThreatOfflineContainer.addReference(hostilRef);
-            }
-            else
-            {
-                if (getCurrentVictim() && hostilRef->getThreat() > (1.1f * getCurrentVictim()->getThreat()))
-                    setDirty(true);
-                iThreatContainer.addReference(hostilRef);
-                iThreatOfflineContainer.remove(hostilRef);
-            }
-            break;
-        case UEV_THREAT_REF_REMOVE_FROM_LIST:
-            if (hostilRef == getCurrentVictim())
-            {
-                setCurrentVictim(nullptr);
-                setDirty(true);
-            }
-            iOwner->SendRemoveFromThreatListOpcode(hostilRef);
-            if (hostilRef->isOnline())
-                iThreatContainer.remove(hostilRef);
-            else
-                iThreatOfflineContainer.remove(hostilRef);
-            break;
-    }
+    _sortedThreatList.erase(ref->_handle);
+    if (sendRemove && ref->IsOnline())
+        SendRemoveToClients(ref->_victim);
 }
 
-bool ThreatManager::isNeedUpdateToClient(uint32 time)
+void ThreatManager::PutThreatenedByMeRef(ObjectGuid const& guid, ThreatReference* ref)
 {
-    if (isThreatListEmpty())
-        return false;
-
-    if (time >= iUpdateTimer)
-    {
-        iUpdateTimer = THREAT_UPDATE_INTERVAL;
-        return true;
-    }
-    iUpdateTimer -= time;
-    return false;
+    auto& inMap = _threatenedByMe[guid];
+    ASSERT(!inMap && "Duplicate entry being inserted into threatened by me list - potential memory leak!");
+    inMap = ref;
 }
 
-// Reset all aggro without modifying the threatlist.
-void ThreatManager::resetAllAggro()
+void ThreatManager::PurgeThreatenedByMeRef(ObjectGuid const& guid)
 {
-    ThreatContainer::StorageType &threatList = iThreatContainer.iThreatList;
-    if (threatList.empty())
-        return;
-
-    for (ThreatContainer::StorageType::iterator itr = threatList.begin(); itr != threatList.end(); ++itr)
-        (*itr)->setThreat(0);
+    auto it = _threatenedByMe.find(guid);
+    if (it != _threatenedByMe.end())
+        _threatenedByMe.erase(it);
+}
 
-    setDirty(true);
+void ThreatManager::UpdateRedirectInfo()
+{
+    _redirectInfo.clear();
+    uint32 totalPct = 0;
+    for (auto const& pair : _redirectRegistry) // (spellid, victim -> pct)
+        for (auto const& victimPair : pair.second) // (victim,pct)
+        {
+            uint32 thisPct = std::min<uint32>(100 - totalPct, victimPair.second);
+            if (thisPct > 0)
+            {
+                _redirectInfo.push_back({ victimPair.first, thisPct });
+                totalPct += thisPct;
+                ASSERT(totalPct <= 100);
+                if (totalPct == 100)
+                    return;
+            }
+        }
 }
diff --git a/src/server/game/Combat/ThreatManager.h b/src/server/game/Combat/ThreatManager.h
index 7066794e5b7..486db4d7e13 100644
--- a/src/server/game/Combat/ThreatManager.h
+++ b/src/server/game/Combat/ThreatManager.h
@@ -15,320 +15,261 @@
  * with this program. If not, see <http://www.gnu.org/licenses/>.
  */
 
-#ifndef _THREATMANAGER
-#define _THREATMANAGER
+ #ifndef TRINITY_THREATMANAGER_H
+ #define TRINITY_THREATMANAGER_H
 
 #include "Common.h"
-#include "SharedDefines.h"
-#include "LinkedReference/Reference.h"
-#include "UnitEvents.h"
-#include "ObjectGuid.h"
 #include "IteratorPair.h"
-
-#include <list>
-
-//==============================================================
+#include "ObjectGuid.h"
+#include "SharedDefines.h"
+#include <boost/heap/fibonacci_heap.hpp>
+#include <unordered_map>
+#include <vector>
 
 class Unit;
-class Creature;
-class ThreatManager;
 class SpellInfo;
 
-#define THREAT_UPDATE_INTERVAL 1 * IN_MILLISECONDS    // Server should send threat update to client periodically each second
-
-//==============================================================
-// Class to calculate the real threat based
-
-struct TC_GAME_API ThreatCalcHelper
+/********************************************************************************************************************************************************\
+ *                                                           DEV DOCUMENTATION: THREAT SYSTEM                                                           *
+ *                                            (future devs: please keep this up-to-date if you change the system)                                       *
+ * The threat system works based on dynamically allocated threat list entries.                                                                          *
+ *                                                                                                                                                      *
+ * Each such entry is a ThreatReference object, which is always stored in exactly three places:                                                         *
+ *  - The threatened unit's (from now: reference "owner") sorted and unsorted threat lists                                                              *
+ *  - The threatening unit's (from now: reference "victim") threatened-by-me list                                                                       *
+ * A ThreatReference object carries the following implicit guarantees:                                                                                  *
+ *  - Both owner and victim are valid units, which are currently in the world. Neither can be nullptr.                                                  *
+ *  - There is an active combat reference between owner and victim.                                                                                     *
+ *                                                                                                                                                      *
+ * ThreatManager also keeps track of whether its owner is engaged (a boolean flag).                                                                     *
+ *  - If a (non-offline) threat list entry is added to a not-yet-engaged ThreatManager, it calls JustEngagedWith on its owner's AI.                         *
+ *  - The engaged state is cleared in ClearAllThreat (which is invoked on evade).                                                                       *
+ *  - This flag can be accessed through the IsEngaged method. For creatures that can have a threat list, this is equal to Unit::IsEngaged.              *
+ *                                                                                                                                                      *
+ * Note that (threat => combat) is a strong guarantee provided in conjunction with CombatManager. Thus:                                                 *
+ *  - Adding threat will also create a combat reference between the units if one doesn't exist yet (even if the owner can't have a threat list!)        *
+ *  - Ending combat between two units will also delete any threat references that may exist between them.                                               *
+ *                                                                                                                                                      *
+ * To manage a creature's threat list, ThreatManager maintains a heap of threat reference const pointers.                                               *
+ * This heap is kept well-structured in all methods that modify ThreatReference, and is used to select the next target.                                 *
+ *                                                                                                                                                      *
+ * Selection uses the following properties on ThreatReference, in order:                                                                                *
+ * - Online state (one of ONLINE, SUPPRESSED, OFFLINE):                                                                                                 *
+ *   - ONLINE:     Normal threat state, target is valid and attackable                                                                                  *
+ *   - SUPPRESSED: Target is attackable, but fully immuned. This is used for targets under HoP, Divine Shield, Ice Block etc.                           *
+ *                 Targets with SUPPRESSED threat can still be valid targets, but any target with ONLINE threat will be preferred.                      *
+ *   - OFFLINE:    The target is, for whatever reason, not valid at this time (for example, IMMUNE_TO_X flags or game master state).                    *
+ *                 These targets can never be selected by SelectVictim, which will return nullptr if all targets are OFFLINE (typically causing evade). *
+ *   - Related methods: GetOnlineState, IsOnline, IsAvailable, IsOffline                                                                                *
+ * - Taunt state (one of TAUNT, NONE, DETAUNT), the names speak for themselves                                                                          *
+ *   - Related methods: GetTauntState, IsTaunting, IsDetaunted                                                                                          *
+ * - Actual threat value (GetThreat)                                                                                                                    *
+ *                                                                                                                                                      *
+ * The current (= last selected) victim can be accessed using GetCurrentVictim. SelectVictim selects a (potentially new) victim.                        *
+ * Beyond that, ThreatManager has a variety of helpers and notifiers, which are documented inline below.                                                *
+ *                                                                                                                                                      *
+ * SPECIAL NOTE: Please be aware that any heap iterator may be invalidated if you modify a ThreatReference. The heap holds const pointers for a reason. *
+ *               If you need to modify multiple ThreatReference objects, then use GetModifiableThreatList(), which is safe to modify!                   *
+\********************************************************************************************************************************************************/
+
+class ThreatReference;
+struct CompareThreatLessThan
 {
-    static float calcThreat(Unit* hatedUnit, Unit* hatingUnit, float threat, SpellSchoolMask schoolMask = SPELL_SCHOOL_MASK_NORMAL, SpellInfo const* threatSpell = nullptr);
-    static bool isValidProcess(Unit* hatedUnit, Unit* hatingUnit, SpellInfo const* threatSpell = nullptr);
+    CompareThreatLessThan() {}
+    bool operator()(ThreatReference const* a, ThreatReference const* b) const;
 };
 
-//==============================================================
-class TC_GAME_API HostileReference : public Reference<Unit, ThreatManager>
+// Please check Game/Combat/ThreatManager.h for documentation on how this class works!
+class TC_GAME_API ThreatManager
 {
     public:
-        HostileReference(Unit* refUnit, ThreatManager* threatManager, float threat);
-
-        // -- compatibility layer for combat rewrite (PR #19930)
-        Unit* GetOwner() const;
-        Unit* GetVictim() const { return getTarget(); }
-        void AddThreat(float amt) { addThreat(amt); }
-        void SetThreat(float amt) { setThreat(amt); }
-        void ModifyThreatByPercent(int32 pct) { addThreatPercent(pct); }
-        void ScaleThreat(float factor) { setThreat(iThreat*factor); }
-        bool IsOnline() const { return iOnline; }
-        bool IsAvailable() const { return iOnline; }
-        bool IsOffline() const { return !iOnline; }
-        float GetThreat() const { return getThreat(); }
-        void ClearThreat() { removeReference(); }
-
-        //=================================================
-        void addThreat(float modThreat);
-
-        void setThreat(float threat) { addThreat(threat - iThreat); }
-
-        void addThreatPercent(int32 percent);
-
-        float getThreat() const { return iThreat + iTempThreatModifier; }
-
-        bool isOnline() const { return iOnline; }
-
-        // The Unit might be in water and the creature can not enter the water, but has range attack
-        // in this case online = true, but accessible = false
-        bool isAccessible() const { return iAccessible; }
-
-        // used for temporary setting a threat and reducing it later again.
-        // the threat modification is stored
-        void setTempThreat(float threat)
-        {
-            addTempThreat(threat - iTempThreatModifier);
-        }
-
-        void addTempThreat(float threat)
-        {
-            if (!threat)
-                return;
-
-            iTempThreatModifier += threat;
-
-            ThreatRefStatusChangeEvent event(UEV_THREAT_REF_THREAT_CHANGE, this, threat);
-            fireStatusChanged(event);
-        }
-
-        void resetTempThreat()
-        {
-            addTempThreat(-iTempThreatModifier);
-        }
-
-        float getTempThreatModifier() { return iTempThreatModifier; }
-
-        //=================================================
-        // check, if source can reach target and set the status
-        void updateOnlineStatus();
-
-        void setOnlineOfflineState(bool isOnline);
-
-        void setAccessibleState(bool isAccessible);
-        //=================================================
-
-        bool operator==(HostileReference const& hostileRef) const { return hostileRef.getUnitGuid() == getUnitGuid(); }
-
-        //=================================================
-
-        ObjectGuid getUnitGuid() const { return iUnitGuid; }
-
-        //=================================================
-        // reference is not needed anymore. realy delete it !
-
-        void removeReference();
-
-        //=================================================
-
-        HostileReference* next() { return static_cast<HostileReference*>(Reference<Unit, ThreatManager>::next()); }
-
-        //=================================================
-
-        // Tell our refTo (target) object that we have a link
-        void targetObjectBuildLink() override;
-
-        // Tell our refTo (taget) object, that the link is cut
-        void targetObjectDestroyLink() override;
-
-        // Tell our refFrom (source) object, that the link is cut (Target destroyed)
-        void sourceObjectDestroyLink() override;
-
-    private:
-        // Inform the source, that the status of that reference was changed
-        void fireStatusChanged(ThreatRefStatusChangeEvent& threatRefStatusChangeEvent);
+        typedef boost::heap::fibonacci_heap<ThreatReference const*, boost::heap::compare<CompareThreatLessThan>> threat_list_heap;
+        static const uint32 CLIENT_THREAT_UPDATE_INTERVAL = 1000u;
+
+        static bool CanHaveThreatList(Unit const* who);
+
+        ThreatManager(Unit* owner);
+        // called from ::Create methods just after construction (once all fields on owner have been populated)
+        // should not be called from anywhere else
+        void Initialize();
+        // called from Creature::Update (only creatures can have their own threat list)
+        // should not be called from anywhere else
+        void Update(uint32 tdiff);
+
+        // never nullptr
+        Unit* GetOwner() const { return _owner; }
+        // can our owner have a threat list?
+        // identical to ThreatManager::CanHaveThreatList(GetOwner())
+        bool CanHaveThreatList() const { return _ownerCanHaveThreatList; }
+        // returns the victim selected by the last SelectVictim call - this can be nullptr
+        Unit* GetCurrentVictim() const;
+        // returns an arbitrary non-offline victim from owner's threat list if one exists, nullptr otherwise
+        Unit* GetAnyTarget() const;
+        // selects a (potentially new) victim from the threat list and returns it - this can be nullptr
+        Unit* SelectVictim();
+
+        bool IsEngaged() const { return _ownerEngaged; }
+        // are there any entries in owner's threat list?
+        bool IsThreatListEmpty(bool includeOffline = false) const;
+        // is there a threat list entry on owner's threat list with victim == who?
+        bool IsThreatenedBy(ObjectGuid const& who, bool includeOffline = false) const;
+        // is there a threat list entry on owner's threat list with victim == who?
+        bool IsThreatenedBy(Unit const* who, bool includeOffline = false) const;
+        // returns ThreatReference amount if a ref exists, 0.0f otherwise
+        float GetThreat(Unit const* who, bool includeOffline = false) const;
+        size_t GetThreatListSize() const { return _sortedThreatList.size(); }
+        // fastest of the three threat list getters - gets the threat list in "arbitrary" order
+        Trinity::IteratorPair<threat_list_heap::const_iterator> GetUnsortedThreatList() const { return { _sortedThreatList.begin(), _sortedThreatList.end() }; }
+        // slightly slower than GetUnsorted, but, well...sorted - only use it if you need the sorted property, of course
+        // note: current tank is NOT guaranteed to be the first entry in this list - check GetCurrentVictim separately if you want that!
+        Trinity::IteratorPair<threat_list_heap::ordered_iterator> GetSortedThreatList() const { return { _sortedThreatList.ordered_begin(), _sortedThreatList.ordered_end() }; }
+        // slowest of the three threat list getters (by far), but lets you modify the threat references
+        std::vector<ThreatReference*> GetModifiableThreatList() const;
+
+        // does any unit have a threat list entry with victim == this.owner?
+        bool IsThreateningAnyone(bool includeOffline = false) const;
+        // is there a threat list entry on who's threat list for this.owner?
+        bool IsThreateningTo(ObjectGuid const& who, bool includeOffline = false) const;
+        // is there a threat list entry on who's threat list for this.owner?
+        bool IsThreateningTo(Unit const* who, bool includeOffline = false) const;
+        auto const& GetThreatenedByMeList() const { return _threatenedByMe; }
+
+        // Notify the ThreatManager that a condition changed that may impact refs' online state so it can re-evaluate
+        void UpdateOnlineStates(bool meThreateningOthers = true, bool othersThreateningMe = true);
+        ///== AFFECT MY THREAT LIST ==
+        void AddThreat(Unit* target, float amount, SpellInfo const* spell = nullptr, bool ignoreModifiers = false, bool ignoreRedirects = false);
+        void ScaleThreat(Unit* target, float factor);
+        // Modify target's threat by +percent%
+        void ModifyThreatByPercent(Unit* target, int32 percent) { if (percent) ScaleThreat(target, 0.01f*float(100 + percent)); }
+        // Resets the specified unit's threat to zero
+        void ResetThreat(Unit* target) { ScaleThreat(target, 0.0f); }
+        // Sets the specified unit's threat to be equal to the highest entry on the threat list
+        void MatchUnitThreatToHighestThreat(Unit* target);
+        // Notify the ThreatManager that we have a new taunt aura (or a taunt aura expired)
+        void TauntUpdate();
+        // Sets all threat refs in owner's threat list to have zero threat
+        void ResetAllThreat();
+        // Removes specified target from the threat list
+        void ClearThreat(Unit* target);
+        // Removes all targets from the threat list (will cause evade in UpdateVictim if called)
+        void ClearAllThreat();
 
-        Unit* GetSourceUnit();
+        // sends SMSG_THREAT_UPDATE to all nearby clients (used by client to forward threat list info to addons)
+        void SendThreatListToClients() const;
+
+        ///== AFFECT OTHERS' THREAT LISTS ==
+        // what it says on the tin - call AddThreat on everything that's threatened by us with the specified params
+        void ForwardThreatForAssistingMe(Unit* assistant, float baseAmount, SpellInfo const* spell = nullptr, bool ignoreModifiers = false);
+        // delete all ThreatReferences with victim == owner
+        void RemoveMeFromThreatLists();
+        // re-calculates the temporary threat modifier from auras on myself
+        void UpdateMyTempModifiers();
+        // re-calculate SPELL_AURA_MOD_THREAT modifiers
+        void UpdateMySpellSchoolModifiers();
+
+        ///== REDIRECT SYSTEM ==
+        // Register a redirection effect that redirects pct% of threat generated by owner to victim
+        void RegisterRedirectThreat(uint32 spellId, ObjectGuid const& victim, uint32 pct);
+        // Unregister a redirection effort for all victims
+        void UnregisterRedirectThreat(uint32 spellId);
+        // Unregister a redirection effect for a specific victim
+        void UnregisterRedirectThreat(uint32 spellId, ObjectGuid const& victim);
 
     private:
-        float iThreat;
-        float iTempThreatModifier;                          // used for SPELL_AURA_MOD_TOTAL_THREAT
-
-        ObjectGuid iUnitGuid;
-        bool iOnline;
-        bool iAccessible;
-};
-
-//==============================================================
-class ThreatManager;
-
-class TC_GAME_API ThreatContainer
-{
-        friend class ThreatManager;
+        Unit* const _owner;
+        bool _ownerCanHaveThreatList;
+        bool _ownerEngaged;
+
+        static const CompareThreatLessThan CompareThreat;
+        static bool CompareReferencesLT(ThreatReference const* a, ThreatReference const* b, float aWeight);
+        static float CalculateModifiedThreat(float threat, Unit const* victim, SpellInfo const* spell);
+
+        // send opcodes (all for my own threat list)
+        void SendClearAllThreatToClients() const;
+        void SendRemoveToClients(Unit const* victim) const;
+        void SendNewVictimToClients(ThreatReference const* victimRef) const;
+
+        ///== MY THREAT LIST ==
+        void PutThreatListRef(ObjectGuid const& guid, ThreatReference* ref);
+        void PurgeThreatListRef(ObjectGuid const& guid, bool sendRemove);
+
+        uint32 _updateClientTimer;
+        threat_list_heap _sortedThreatList;
+        std::unordered_map<ObjectGuid, ThreatReference*> _myThreatListEntries;
+        ThreatReference const* _currentVictimRef;
+        ThreatReference const* ReselectVictim();
+
+        ///== OTHERS' THREAT LISTS ==
+        void PutThreatenedByMeRef(ObjectGuid const& guid, ThreatReference* ref);
+        void PurgeThreatenedByMeRef(ObjectGuid const& guid);
+        std::unordered_map<ObjectGuid, ThreatReference*> _threatenedByMe; // these refs are entries for myself on other units' threat lists
+        float _singleSchoolModifiers[MAX_SPELL_SCHOOL]; // most spells are single school - we pre-calculate these and store them
+        mutable std::unordered_map<std::underlying_type<SpellSchoolMask>::type, float> _multiSchoolModifiers; // these are calculated on demand
+
+        // redirect system (is kind of dumb, but that's because none of the redirection spells actually have any aura effect associated with them, so spellscript needs to deal with it)
+        void UpdateRedirectInfo();
+        std::vector<std::pair<ObjectGuid, uint32>> _redirectInfo; // current redirection targets and percentages (updated from registry in ThreatManager::UpdateRedirectInfo)
+        std::unordered_map<uint32, std::unordered_map<ObjectGuid, uint32>> _redirectRegistry; // spellid -> (victim -> pct); all redirection effects on us (removal individually managed by spell scripts because blizzard is dumb)
 
     public:
-        typedef std::list<HostileReference*> StorageType;
+        ThreatManager(ThreatManager const&) = delete;
+        ThreatManager& operator=(ThreatManager const&) = delete;
 
-        ThreatContainer(): iDirty(false) { }
-
-        ~ThreatContainer() { clearReferences(); }
-
-        HostileReference* addThreat(Unit* victim, float threat);
-
-        void ModifyThreatByPercent(Unit* victim, int32 percent);
-
-        HostileReference* selectNextVictim(Creature* attacker, HostileReference* currentVictim) const;
-
-        void setDirty(bool isDirty) { iDirty = isDirty; }
-
-        bool isDirty() const { return iDirty; }
-
-        bool empty() const
-        {
-            return iThreatList.empty();
-        }
-
-        HostileReference* getMostHated() const
-        {
-            return iThreatList.empty() ? nullptr : iThreatList.front();
-        }
-
-        HostileReference* getReferenceByTarget(Unit const* victim) const;
-
-        StorageType const & getThreatList() const { return iThreatList; }
-
-    private:
-        void remove(HostileReference* hostileRef)
-        {
-            iThreatList.remove(hostileRef);
-        }
-
-        void addReference(HostileReference* hostileRef)
-        {
-            iThreatList.push_back(hostileRef);
-        }
-
-        void clearReferences();
-
-        // Sort the list if necessary
-        void update();
-
-        StorageType iThreatList;
-        bool iDirty;
+    friend class ThreatReference;
+    friend struct CompareThreatLessThan;
 };
 
-//=================================================
-
-typedef HostileReference ThreatReference;
-class TC_GAME_API ThreatManager
+// Please check Game/Combat/ThreatManager.h for documentation on how this class works!
+class TC_GAME_API ThreatReference
 {
     public:
-        // -- compatibility layer for combat rewrite (PR #19930)
-        Trinity::IteratorPair<std::list<ThreatReference*>::const_iterator> GetSortedThreatList() const { auto& list = iThreatContainer.getThreatList(); return { list.cbegin(), list.cend() }; }
-        Trinity::IteratorPair<std::list<ThreatReference*>::const_iterator> GetUnsortedThreatList() const { return GetSortedThreatList(); }
-        std::list<ThreatReference*> GetModifiableThreatList() const { return iThreatContainer.getThreatList(); }
-        Unit* SelectVictim() { return getHostilTarget(); }
-        Unit* GetCurrentVictim() const { if (ThreatReference* ref = getCurrentVictim()) return ref->GetVictim(); else return nullptr; }
-        bool IsThreatListEmpty(bool includeOffline = false) const { return includeOffline ? areThreatListsEmpty() : isThreatListEmpty(); }
-        bool IsThreatenedBy(Unit const* who, bool includeOffline = false) const { return (FindReference(who, includeOffline) != nullptr); }
-        size_t GetThreatListSize() const { return iThreatContainer.iThreatList.size(); }
-        void ForwardThreatForAssistingMe(Unit* victim, float amount, SpellInfo const* spell, bool ignoreModifiers = false, bool ignoreRedirection = false);
-        Unit* GetAnyTarget() const { auto const& list = getThreatList(); if (!list.empty()) return list.front()->getTarget(); return nullptr; }
-        void ResetThreat(Unit const* who) { if (auto* ref = FindReference(who, true)) ref->setThreat(0.0f); }
-        void ResetAllThreat() { resetAllAggro(); }
-        float GetThreat(Unit const* who, bool includeOffline = false) const { if (auto* ref = FindReference(who, includeOffline)) return ref->GetThreat(); return 0.0f; }
-        void ClearThreat(Unit const* who) { if (auto* ref = FindReference(who, true)) ref->removeReference(); }
-        void ClearAllThreat();
-        void AddThreat(Unit* victim, float amount, SpellInfo const* spell = nullptr, bool ignoreModifiers = false, bool ignoreRedirection = false);
+        enum TauntState { TAUNT_STATE_DETAUNT = -1, TAUNT_STATE_NONE = 0, TAUNT_STATE_TAUNT = 1 };
+        enum OnlineState { ONLINE_STATE_ONLINE = 2, ONLINE_STATE_SUPPRESSED = 1, ONLINE_STATE_OFFLINE = 0 };
+
+        Unit* GetOwner() const { return _owner; }
+        Unit* GetVictim() const { return _victim; }
+        float GetThreat() const { return std::max<float>(_baseAmount + (float)_tempModifier, 0.0f); }
+        OnlineState GetOnlineState() const { return _online; }
+        bool IsOnline() const { return (_online >= ONLINE_STATE_ONLINE); }
+        bool IsAvailable() const { return (_online > ONLINE_STATE_OFFLINE); }
+        bool IsOffline() const { return (_online <= ONLINE_STATE_OFFLINE); }
+        TauntState GetTauntState() const { return _taunted; }
+        bool IsTaunting() const { return _taunted == TAUNT_STATE_TAUNT; }
+        bool IsDetaunted() const { return _taunted == TAUNT_STATE_DETAUNT; }
+
+        void SetThreat(float amount) { _baseAmount = amount; HeapNotifyChanged(); }
+        void AddThreat(float amount);
+        void ScaleThreat(float factor);
+        void ModifyThreatByPercent(int32 percent) { if (percent) ScaleThreat(0.01f*float(100 + percent)); }
+        void UpdateOnlineState();
+
+        void ClearThreat(bool sendRemove = true); // dealloc's this
+
     private:
-        HostileReference* FindReference(Unit const* who, bool includeOffline) const { if (auto* ref = iThreatContainer.getReferenceByTarget(who)) return ref; if (includeOffline) if (auto* ref = iThreatOfflineContainer.getReferenceByTarget(who)) return ref; return nullptr; }
+        ThreatReference(ThreatManager* mgr, Unit* victim, float amount) : _owner(mgr->_owner), _mgr(mgr), _victim(victim), _baseAmount(amount), _tempModifier(0), _online(SelectOnlineState()), _taunted(TAUNT_STATE_NONE) { }
+        static bool FlagsAllowFighting(Unit const* a, Unit const* b);
+        OnlineState SelectOnlineState();
+        void UpdateTauntState(bool victimIsTaunting);
+        Unit* const _owner;
+        ThreatManager* const _mgr;
+        void HeapNotifyIncreased() { _mgr->_sortedThreatList.increase(_handle); }
+        void HeapNotifyDecreased() { _mgr->_sortedThreatList.decrease(_handle); }
+        void HeapNotifyChanged() { _mgr->_sortedThreatList.update(_handle); }
+        Unit* const _victim;
+        float _baseAmount;
+        int32 _tempModifier; // Temporary effects (auras with SPELL_AURA_MOD_TOTAL_THREAT) - set from victim's threatmanager in ThreatManager::UpdateMyTempModifiers
+        OnlineState _online;
+        TauntState _taunted;
+        ThreatManager::threat_list_heap::handle_type _handle;
 
     public:
+        ThreatReference(ThreatReference const&) = delete;
+        ThreatReference& operator=(ThreatReference const&) = delete;
 
-        friend class HostileReference;
-
-        explicit ThreatManager(Unit* owner);
-
-        ~ThreatManager() { clearReferences(); }
-
-        void clearReferences();
-
-        void addThreat(Unit* victim, float threat, SpellSchoolMask schoolMask = SPELL_SCHOOL_MASK_NORMAL, SpellInfo const* threatSpell = nullptr);
-
-        void doAddThreat(Unit* victim, float threat);
-
-        void ModifyThreatByPercent(Unit* victim, int32 percent);
-
-        float getThreat(Unit* victim, bool alsoSearchOfflineList = false);
-
-        bool isThreatListEmpty() const { return iThreatContainer.empty(); }
-        bool areThreatListsEmpty() const { return iThreatContainer.empty() && iThreatOfflineContainer.empty(); }
-
-        void processThreatEvent(ThreatRefStatusChangeEvent* threatRefStatusChangeEvent);
-
-        bool isNeedUpdateToClient(uint32 time);
-
-        HostileReference* getCurrentVictim() const { return iCurrentVictim; }
-
-        Unit* GetOwner() const { return iOwner; }
-
-        Unit* getHostilTarget();
-
-        void tauntApply(Unit* taunter);
-        void tauntFadeOut(Unit* taunter);
-
-        void setCurrentVictim(HostileReference* hostileRef);
-
-        void setDirty(bool isDirty) { iThreatContainer.setDirty(isDirty); }
-
-        // Reset all aggro without modifying the threadlist.
-        void resetAllAggro();
-
-        // Reset all aggro of unit in threadlist satisfying the predicate.
-        template<class PREDICATE> void resetAggro(PREDICATE predicate)
-        {
-            ThreatContainer::StorageType &threatList = iThreatContainer.iThreatList;
-            if (threatList.empty())
-                return;
-
-            for (ThreatContainer::StorageType::iterator itr = threatList.begin(); itr != threatList.end(); ++itr)
-            {
-                HostileReference* ref = (*itr);
-
-                if (predicate(ref->getTarget()))
-                {
-                    ref->setThreat(0);
-                    setDirty(true);
-                }
-            }
-        }
-
-        // methods to access the lists from the outside to do some dirty manipulation (scriping and such)
-        // I hope they are used as little as possible.
-        ThreatContainer::StorageType const & getThreatList() const { return iThreatContainer.getThreatList(); }
-        ThreatContainer::StorageType const & getOfflineThreatList() const { return iThreatOfflineContainer.getThreatList(); }
-        ThreatContainer& getOnlineContainer() { return iThreatContainer; }
-        ThreatContainer& getOfflineContainer() { return iThreatOfflineContainer; }
-    private:
-        void _addThreat(Unit* victim, float threat);
-
-        HostileReference* iCurrentVictim;
-        Unit* iOwner;
-        uint32 iUpdateTimer;
-        ThreatContainer iThreatContainer;
-        ThreatContainer iThreatOfflineContainer;
+    friend class ThreatManager;
+    friend struct CompareThreatLessThan;
 };
 
-//=================================================
+inline bool CompareThreatLessThan::operator()(ThreatReference const* a, ThreatReference const* b) const { return ThreatManager::CompareReferencesLT(a, b, 1.0f); }
 
-namespace Trinity
-{
-    // Binary predicate for sorting HostileReferences based on threat value
-    class ThreatOrderPred
-    {
-        public:
-            ThreatOrderPred(bool ascending = false) : m_ascending(ascending) { }
-            bool operator() (HostileReference const* a, HostileReference const* b) const
-            {
-                return m_ascending ? a->getThreat() < b->getThreat() : a->getThreat() > b->getThreat();
-            }
-        private:
-            const bool m_ascending;
-    };
-}
-#endif
+ #endif
diff --git a/src/server/game/Combat/UnitEvents.h b/src/server/game/Combat/UnitEvents.h
deleted file mode 100644
index fec0f089ac7..00000000000
--- a/src/server/game/Combat/UnitEvents.h
+++ /dev/null
@@ -1,121 +0,0 @@
-/*
- * This file is part of the TrinityCore Project. See AUTHORS file for Copyright information
- *
- * This program is free software; you can redistribute it and/or modify it
- * under the terms of the GNU General Public License as published by the
- * Free Software Foundation; either version 2 of the License, or (at your
- * option) any later version.
- *
- * This program is distributed in the hope that it will be useful, but WITHOUT
- * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
- * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
- * more details.
- *
- * You should have received a copy of the GNU General Public License along
- * with this program. If not, see <http://www.gnu.org/licenses/>.
- */
-
-#ifndef _UNITEVENTS
-#define _UNITEVENTS
-
-#include "Common.h"
-
-class ThreatContainer;
-class ThreatManager;
-class HostileReference;
-
-//==============================================================
-//==============================================================
-
-enum UNIT_EVENT_TYPE
-{
-    // Player/Pet changed on/offline status
-    UEV_THREAT_REF_ONLINE_STATUS        = 1<<0,
-
-    // Threat for Player/Pet changed
-    UEV_THREAT_REF_THREAT_CHANGE        = 1<<1,
-
-    // Player/Pet will be removed from list (dead) [for internal use]
-    UEV_THREAT_REF_REMOVE_FROM_LIST     = 1<<2,
-
-    // Player/Pet entered/left  water or some other place where it is/was not accessible for the creature
-    UEV_THREAT_REF_ACCESSIBLE_STATUS    = 1<<3,
-
-    // Threat list is going to be sorted (if dirty flag is set)
-    UEV_THREAT_SORT_LIST                = 1<<4,
-
-    // New target should be fetched, could tbe the current target as well
-    UEV_THREAT_SET_NEXT_TARGET          = 1<<5,
-
-    // A new victim (target) was set. Could be NULL
-    UEV_THREAT_VICTIM_CHANGED           = 1<<6
-
-    // Future use
-    //UEV_UNIT_KILLED                   = 1<<7,
-
-    //Future use
-    //UEV_UNIT_HEALTH_CHANGE            = 1<<8,
-};
-
-#define UEV_THREAT_REF_EVENT_MASK (UEV_THREAT_REF_ONLINE_STATUS | UEV_THREAT_REF_THREAT_CHANGE | UEV_THREAT_REF_REMOVE_FROM_LIST | UEV_THREAT_REF_ACCESSIBLE_STATUS)
-#define UEV_THREAT_MANAGER_EVENT_MASK (UEV_THREAT_SORT_LIST | UEV_THREAT_SET_NEXT_TARGET | UEV_THREAT_VICTIM_CHANGED)
-#define UEV_ALL_EVENT_MASK (0xffffffff)
-
-// Future use
-//#define UEV_UNIT_EVENT_MASK (UEV_UNIT_KILLED | UEV_UNIT_HEALTH_CHANGE)
-
-//==============================================================
-
-class UnitBaseEvent
-{
-    public:
-        explicit UnitBaseEvent(uint32 pType) { iType = pType; }
-        uint32 getType() const { return iType; }
-        bool matchesTypeMask(uint32 pMask) const { return (iType & pMask) != 0; }
-
-    private:
-        uint32 iType;
-
-    protected:
-        ~UnitBaseEvent() { }
-};
-
-//==============================================================
-
-class TC_GAME_API ThreatRefStatusChangeEvent : public UnitBaseEvent
-{
-    private:
-        HostileReference* iHostileReference;
-        union
-        {
-            float iFValue;
-            int32 iIValue;
-            bool iBValue;
-        };
-        ThreatManager* iThreatManager;
-
-    public:
-        explicit ThreatRefStatusChangeEvent(uint32 pType) : UnitBaseEvent(pType), iHostileReference(nullptr), iThreatManager(nullptr) { }
-
-        ThreatRefStatusChangeEvent(uint32 pType, HostileReference* pHostileReference) : UnitBaseEvent(pType), iHostileReference(pHostileReference), iThreatManager(nullptr) { }
-
-        ThreatRefStatusChangeEvent(uint32 pType, HostileReference* pHostileReference, float pValue) : UnitBaseEvent(pType), iHostileReference(pHostileReference), iFValue(pValue), iThreatManager(nullptr) { }
-
-        ThreatRefStatusChangeEvent(uint32 pType, HostileReference* pHostileReference, bool pValue) : UnitBaseEvent(pType), iHostileReference(pHostileReference), iBValue(pValue), iThreatManager(nullptr) { }
-
-        int32 getIValue() const { return iIValue; }
-
-        float getFValue() const { return iFValue; }
-
-        bool getBValue() const { return iBValue; }
-
-        void setBValue(bool pValue) { iBValue = pValue; }
-
-        HostileReference* getReference() const { return iHostileReference; }
-
-        void setThreatManager(ThreatManager* pThreatManager) { iThreatManager = pThreatManager; }
-
-        ThreatManager* GetThreatManager() const { return iThreatManager; }
-};
-
-#endif
diff --git a/src/server/game/Entities/Creature/Creature.cpp b/src/server/game/Entities/Creature/Creature.cpp
index a8fb84f7f47..e6fd20e73aa 100644
--- a/src/server/game/Entities/Creature/Creature.cpp
+++ b/src/server/game/Entities/Creature/Creature.cpp
@@ -671,6 +671,8 @@ bool Creature::UpdateEntry(uint32 entry, CreatureData const* data /*= nullptr*/,
     UpdateMovementFlags();
     LoadCreaturesAddon();
     LoadTemplateImmunities();
+
+    GetThreatManager().UpdateOnlineStates(true, true);
     return true;
 }
 
@@ -771,6 +773,8 @@ void Creature::Update(uint32 diff)
             if (!IsAlive())
                 break;
 
+            GetThreatManager().Update(diff);
+
             if (m_shouldReacquireTarget && !IsFocusing(nullptr, true))
             {
                 SetTarget(m_suppressedTarget);
@@ -1161,6 +1165,8 @@ bool Creature::Create(ObjectGuid::LowType guidlow, Map* map, uint32 entry, Posit
         ApplySpellImmune(0, IMMUNITY_EFFECT, SPELL_EFFECT_KNOCK_BACK_DEST, true);
     }
 
+    GetThreatManager().Initialize();
+
     return true;
 }
 
@@ -1198,6 +1204,103 @@ Creature* Creature::CreateCreatureFromDB(ObjectGuid::LowType spawnId, Map* map,
     return creature;
 }
 
+Unit* Creature::SelectVictim()
+{
+    Unit* target = nullptr;
+
+    ThreatManager& mgr = GetThreatManager();
+
+    if (mgr.CanHaveThreatList())
+    {
+        target = mgr.SelectVictim();
+        while (!target)
+        {
+            Unit* newTarget = nullptr;
+            // nothing found to attack - try to find something we're in combat with (but don't have a threat entry for yet) and start attacking it
+            for (auto const& pair : GetCombatManager().GetPvECombatRefs())
+            {
+                newTarget = pair.second->GetOther(this);
+                if (!mgr.IsThreatenedBy(newTarget, true))
+                {
+                    mgr.AddThreat(newTarget, 0.0f, nullptr, true, true);
+                    break;
+                }
+                else
+                    newTarget = nullptr;
+            }
+            if (!newTarget)
+                break;
+            target = mgr.SelectVictim();
+        }
+    }
+    else if (!HasReactState(REACT_PASSIVE))
+    {
+        // We're a player pet, probably
+        target = getAttackerForHelper();
+        if (!target && IsSummon())
+        {
+            if (Unit* owner = ToTempSummon()->GetOwner())
+            {
+                if (owner->IsInCombat())
+                    target = owner->getAttackerForHelper();
+                if (!target)
+                {
+                    for (ControlList::const_iterator itr = owner->m_Controlled.begin(); itr != owner->m_Controlled.end(); ++itr)
+                    {
+                        if ((*itr)->IsInCombat())
+                        {
+                            target = (*itr)->getAttackerForHelper();
+                            if (target)
+                                break;
+                        }
+                    }
+                }
+            }
+        }
+    }
+    else
+        return nullptr;
+
+    if (target && _IsTargetAcceptable(target) && CanCreatureAttack(target))
+    {
+        if (!IsFocusing(nullptr, true))
+            SetInFront(target);
+        return target;
+    }
+
+    /// @todo a vehicle may eat some mob, so mob should not evade
+    if (GetVehicle())
+        return nullptr;
+
+    // search nearby enemy before enter evade mode
+    if (HasReactState(REACT_AGGRESSIVE))
+    {
+        target = SelectNearestTargetInAttackDistance(m_CombatDistance ? m_CombatDistance : ATTACK_DISTANCE);
+
+        if (target && _IsTargetAcceptable(target) && CanCreatureAttack(target))
+            return target;
+    }
+
+    Unit::AuraEffectList const& iAuras = GetAuraEffectsByType(SPELL_AURA_MOD_INVISIBILITY);
+    if (!iAuras.empty())
+    {
+        for (Unit::AuraEffectList::const_iterator itr = iAuras.begin(); itr != iAuras.end(); ++itr)
+        {
+            if ((*itr)->GetBase()->IsPermanent())
+            {
+                AI()->EnterEvadeMode(CreatureAI::EVADE_REASON_OTHER);
+                break;
+            }
+        }
+        return nullptr;
+    }
+
+    // enter in evade mode in other case
+    AI()->EnterEvadeMode(CreatureAI::EVADE_REASON_NO_HOSTILES);
+
+    return nullptr;
+}
+
 void Creature::InitializeReactState()
 {
     if (IsTotem() || IsTrigger() || IsCritter() || IsSpiritService())
@@ -3286,6 +3389,37 @@ bool Creature::CanGiveExperience() const
         && !(GetCreatureTemplate()->flags_extra & CREATURE_FLAG_EXTRA_NO_XP_AT_KILL);
 }
 
+void Creature::AtEnterCombat()
+{
+    Unit::AtEnterCombat();
+
+    if (!(GetCreatureTemplate()->type_flags & CREATURE_TYPE_FLAG_MOUNTED_COMBAT_ALLOWED))
+        Dismount();
+
+    if (IsPet() || IsGuardian()) // update pets' speed for catchup OOC speed
+    {
+        UpdateSpeed(MOVE_RUN);
+        UpdateSpeed(MOVE_SWIM);
+        UpdateSpeed(MOVE_FLIGHT);
+    }
+}
+
+void Creature::AtExitCombat()
+{
+    Unit::AtExitCombat();
+
+    ClearUnitState(UNIT_STATE_ATTACK_PLAYER);
+    if (HasDynamicFlag(UNIT_DYNFLAG_TAPPED))
+        SetDynamicFlags(GetCreatureTemplate()->dynamicflags);
+
+    if (IsPet() || IsGuardian()) // update pets' speed for catchup OOC speed
+    {
+        UpdateSpeed(MOVE_RUN);
+        UpdateSpeed(MOVE_SWIM);
+        UpdateSpeed(MOVE_FLIGHT);
+    }
+}
+
 bool Creature::IsEscortNPC(bool onlyIfActive)
 {
     if (!IsAIEnabled)
diff --git a/src/server/game/Entities/Creature/Creature.h b/src/server/game/Entities/Creature/Creature.h
index 6c8ebd2db22..4bd28f76e99 100644
--- a/src/server/game/Entities/Creature/Creature.h
+++ b/src/server/game/Entities/Creature/Creature.h
@@ -102,11 +102,23 @@ class TC_GAME_API Creature : public Unit, public GridObject<Creature>, public Ma
         bool IsDungeonBoss() const { return (GetCreatureTemplate()->flags_extra & CREATURE_FLAG_EXTRA_DUNGEON_BOSS) != 0; }
         bool IsAffectedByDiminishingReturns() const override { return Unit::IsAffectedByDiminishingReturns() || (GetCreatureTemplate()->flags_extra & CREATURE_FLAG_EXTRA_ALL_DIMINISH) != 0; }
 
+        Unit* SelectVictim();
+
         void SetReactState(ReactStates st) { m_reactState = st; }
         ReactStates GetReactState() const { return m_reactState; }
         bool HasReactState(ReactStates state) const { return (m_reactState == state); }
         void InitializeReactState();
 
+        using Unit::IsImmuneToAll;
+        using Unit::SetImmuneToAll;
+        void SetImmuneToAll(bool apply) override { Unit::SetImmuneToAll(apply, HasReactState(REACT_PASSIVE)); }
+        using Unit::IsImmuneToPC;
+        using Unit::SetImmuneToPC;
+        void SetImmuneToPC(bool apply) override { Unit::SetImmuneToPC(apply, HasReactState(REACT_PASSIVE)); }
+        using Unit::IsImmuneToNPC;
+        using Unit::SetImmuneToNPC;
+        void SetImmuneToNPC(bool apply) override { Unit::SetImmuneToNPC(apply, HasReactState(REACT_PASSIVE)); }
+
         /// @todo Rename these properly
         bool isCanInteractWithBattleMaster(Player* player, bool msg) const;
         bool CanResetTalents(Player* player) const;
@@ -303,8 +315,6 @@ class TC_GAME_API Creature : public Unit, public GridObject<Creature>, public Ma
         void SignalFormationMovement(Position const& destination, uint32 id = 0, uint32 moveType = 0, bool orientation = false);
         bool IsFormationLeaderMoveAllowed() const;
 
-        Unit* SelectVictim();
-
         void SetDisableReputationGain(bool disable) { DisableReputationGain = disable; }
         bool IsReputationGainDisabled() const { return DisableReputationGain; }
         bool IsDamageEnoughForLootingAndReward() const { return (m_creatureInfo->flags_extra & CREATURE_FLAG_EXTRA_NO_PLAYER_DAMAGE_REQ) || (m_PlayerDamageReq == 0); }
@@ -346,6 +356,9 @@ class TC_GAME_API Creature : public Unit, public GridObject<Creature>, public Ma
 
         bool CanGiveExperience() const;
 
+        void AtEnterCombat() override;
+        void AtExitCombat() override;
+
     protected:
         bool CreateFromProto(ObjectGuid::LowType guidlow, uint32 entry, CreatureData const* data = nullptr, uint32 vehId = 0);
         bool InitEntry(uint32 entry, CreatureData const* data = nullptr);
diff --git a/src/server/game/Entities/Object/Object.h b/src/server/game/Entities/Object/Object.h
index 530b3aae43f..eb18fa57ee4 100644
--- a/src/server/game/Entities/Object/Object.h
+++ b/src/server/game/Entities/Object/Object.h
@@ -428,6 +428,10 @@ class TC_GAME_API WorldObject : public Object, public WorldLocation
         {
             return GetPhaseShift().CanSee(obj->GetPhaseShift());
         }
+        static bool InSamePhase(WorldObject const* a, WorldObject const* b)
+        {
+            return a && b && a->IsInPhase(b);
+        }
 
         PhaseShift& GetPhaseShift() { return _phaseShift; }
         PhaseShift const& GetPhaseShift() const { return _phaseShift; }
diff --git a/src/server/game/Entities/Pet/Pet.cpp b/src/server/game/Entities/Pet/Pet.cpp
index 36ae708e962..d9cdfe8762a 100644
--- a/src/server/game/Entities/Pet/Pet.cpp
+++ b/src/server/game/Entities/Pet/Pet.cpp
@@ -1630,6 +1630,8 @@ bool Pet::Create(ObjectGuid::LowType guidlow, Map* map, uint32 Entry)
     AddUnitFlag2(UNIT_FLAG2_REGENERATE_POWER);
     SetSheath(SHEATH_STATE_MELEE);
 
+    GetThreatManager().Initialize();
+
     return true;
 }
 
diff --git a/src/server/game/Entities/Player/Player.cpp b/src/server/game/Entities/Player/Player.cpp
index bf9356f5e6a..aabfbf911ee 100644
--- a/src/server/game/Entities/Player/Player.cpp
+++ b/src/server/game/Entities/Player/Player.cpp
@@ -568,6 +568,8 @@ bool Player::Create(ObjectGuid::LowType guidlow, WorldPackets::Character::Charac
         SetPrimarySpecialization(defaultSpec->ID);
     }
 
+    GetThreatManager().Initialize();
+
     return true;
 }
 
@@ -946,7 +948,7 @@ void Player::Update(uint32 p_time)
 
     UpdateAfkReport(now);
 
-    if (GetCombatTimer()) // Only set when in pvp combat
+    if (GetCombatManager().HasPvPCombat())
         if (Aura* aura = GetAura(SPELL_PVP_RULES_ENABLED))
             if (!aura->IsPermanent())
                 aura->SetDuration(aura->GetSpellInfo()->GetMaxDuration());
@@ -1220,7 +1222,7 @@ void Player::Update(uint32 p_time)
         {
             m_hostileReferenceCheckTimer = 15 * IN_MILLISECONDS;
             if (!GetMap()->IsDungeon())
-                getHostileRefManager().deleteReferencesOutOfRange(GetVisibilityRange());
+                GetCombatManager().EndCombatBeyondRange(GetVisibilityRange(), true);
         }
         else
             m_hostileReferenceCheckTimer -= p_time;
@@ -2060,9 +2062,6 @@ void Player::SetInWater(bool inWater)
 
     // Call base
     Unit::SetInWater(inWater);
-
-    // Update threat tables
-    getHostileRefManager().updateThreatTables();
 }
 
 bool Player::IsInAreaTriggerRadius(AreaTriggerEntry const* trigger) const
@@ -2104,15 +2103,11 @@ void Player::SetGameMaster(bool on)
         AddUnitFlag2(UNIT_FLAG2_ALLOW_CHEAT_SPELLS);
 
         if (Pet* pet = GetPet())
-        {
             pet->SetFaction(FACTION_FRIENDLY);
-            pet->getHostileRefManager().setOnlineOfflineState(false);
-        }
 
         RemovePvpFlag(UNIT_BYTE2_FLAG_FFA_PVP);
         ResetContestedPvP();
 
-        getHostileRefManager().setOnlineOfflineState(false);
         CombatStopWithPets();
 
         PhasingHandler::SetAlwaysVisible(this, true, false);
@@ -2130,7 +2125,7 @@ void Player::SetGameMaster(bool on)
         if (Pet* pet = GetPet())
         {
             pet->SetFaction(GetFaction());
-            pet->getHostileRefManager().setOnlineOfflineState(true);
+            pet->GetThreatManager().UpdateOnlineStates();
         }
 
         // restore FFA PvP Server state
@@ -2140,7 +2135,6 @@ void Player::SetGameMaster(bool on)
         // restore FFA PvP area state, remove not allowed for GM mounts
         UpdateArea(m_areaUpdateId);
 
-        getHostileRefManager().setOnlineOfflineState(true);
         m_serverSideVisibilityDetect.SetValue(SERVERSIDE_VISIBILITY_GM, SEC_PLAYER);
     }
 
@@ -22666,7 +22660,6 @@ void Player::CleanupAfterTaxiFlight()
     m_taxi.ClearTaxiDestinations();        // not destinations, clear source node
     Dismount();
     RemoveUnitFlag(UnitFlags(UNIT_FLAG_REMOVE_CLIENT_CONTROL | UNIT_FLAG_TAXI_FLIGHT));
-    getHostileRefManager().setOnlineOfflineState(true);
 }
 
 void Player::ContinueTaxiFlight() const
@@ -25837,6 +25830,20 @@ void Player::ProcessTerrainStatusUpdate(ZLiquidStatus status, Optional<LiquidDat
         m_MirrorTimerFlags &= ~(UNDERWATER_INWATER | UNDERWATER_INLAVA | UNDERWATER_INSLIME | UNDERWATER_INDARKWATER);
 }
 
+void Player::AtEnterCombat()
+{
+    Unit::AtEnterCombat();
+    if (GetCombatManager().HasPvPCombat())
+        EnablePvpRules(true);
+}
+
+void Player::AtExitCombat()
+{
+    Unit::AtExitCombat();
+    UpdatePotionCooldown();
+    m_combatExitTime = getMSTime();
+}
+
 float Player::GetBlockPercent(uint8 attackerLevel) const
 {
     float blockArmor = float(*m_activePlayerData->ShieldBlock);
@@ -26812,7 +26819,7 @@ void Player::DisablePvpRules()
     if (IsInAreaThatActivatesPvpTalents())
         return;
 
-    if (!GetCombatTimer())
+    if (!GetCombatManager().HasPvPCombat())
     {
         RemoveAurasDueToSpell(SPELL_PVP_RULES_ENABLED);
         UpdateItemLevelAreaBasedScaling();
@@ -27983,14 +27990,6 @@ VoidStorageItem* Player::GetVoidStorageItem(uint64 id, uint8& slot) const
     return nullptr;
 }
 
-void Player::OnCombatExit()
-{
-    Unit::OnCombatExit();
-
-    UpdatePotionCooldown();
-    m_combatExitTime = getMSTime();
-}
-
 void Player::CreateGarrison(uint32 garrSiteId)
 {
     std::unique_ptr<Garrison> garrison(new Garrison(this));
diff --git a/src/server/game/Entities/Player/Player.h b/src/server/game/Entities/Player/Player.h
index ad8e9ac1e7a..9e267fdf923 100644
--- a/src/server/game/Entities/Player/Player.h
+++ b/src/server/game/Entities/Player/Player.h
@@ -2012,6 +2012,8 @@ class TC_GAME_API Player : public Unit, public GridObject<Player>
         bool UpdatePosition(float x, float y, float z, float orientation, bool teleport = false) override;
         bool UpdatePosition(Position const& pos, bool teleport = false) override { return UpdatePosition(pos.GetPositionX(), pos.GetPositionY(), pos.GetPositionZ(), pos.GetOrientation(), teleport); }
         void ProcessTerrainStatusUpdate(ZLiquidStatus status, Optional<LiquidData> const& liquidData) override;
+        void AtEnterCombat() override;
+        void AtExitCombat() override;
 
         void SendMessageToSet(WorldPacket const* data, bool self) const override { SendMessageToSetInRange(data, GetVisibilityRange(), self); }
         void SendMessageToSetInRange(WorldPacket const* data, float dist, bool self) const override;
@@ -2528,8 +2530,6 @@ class TC_GAME_API Player : public Unit, public GridObject<Player>
         VoidStorageItem* GetVoidStorageItem(uint8 slot) const;
         VoidStorageItem* GetVoidStorageItem(uint64 id, uint8& slot) const;
 
-        void OnCombatExit() override;
-
         void CreateGarrison(uint32 garrSiteId);
         void DeleteGarrison();
         Garrison* GetGarrison() const { return _garrison.get(); }
diff --git a/src/server/game/Entities/Unit/Unit.cpp b/src/server/game/Entities/Unit/Unit.cpp
index a606cd14190..ba8ce866e7f 100644
--- a/src/server/game/Entities/Unit/Unit.cpp
+++ b/src/server/game/Entities/Unit/Unit.cpp
@@ -295,13 +295,13 @@ SpellNonMeleeDamage::SpellNonMeleeDamage(Unit* _attacker, Unit* _target, SpellIn
 
 Unit::Unit(bool isWorldObject) :
     WorldObject(isWorldObject), m_playerMovingMe(nullptr), m_lastSanctuaryTime(0),
-    IsAIEnabled(false), NeedChangeAI(false), LastCharmerGUID(),
-    m_ControlledByPlayer(false), movespline(new Movement::MoveSpline()),
-    i_AI(nullptr), i_disabledAI(nullptr), m_AutoRepeatFirstCast(false), m_procDeep(0),
-    m_removedAurasCount(0), m_interruptMask(SpellAuraInterruptFlags::None), m_interruptMask2(SpellAuraInterruptFlags2::None),
-    i_motionMaster(new MotionMaster(this)), m_regenTimer(0), m_ThreatManager(this),
-    m_vehicle(nullptr), m_vehicleKit(nullptr), m_unitTypeMask(UNIT_MASK_NONE), m_Diminishing(),
-    m_HostileRefManager(this), _aiAnimKitId(0), _movementAnimKitId(0), _meleeAnimKitId(0),
+    IsAIEnabled(false), NeedChangeAI(false), LastCharmerGUID(), m_ControlledByPlayer(false),
+    movespline(new Movement::MoveSpline()), i_AI(nullptr), i_disabledAI(nullptr),
+    m_AutoRepeatFirstCast(false), m_procDeep(0), m_removedAurasCount(0),
+    m_interruptMask(SpellAuraInterruptFlags::None), m_interruptMask2(SpellAuraInterruptFlags2::None),
+    i_motionMaster(new MotionMaster(this)), m_regenTimer(0), m_vehicle(nullptr),
+    m_vehicleKit(nullptr), m_unitTypeMask(UNIT_MASK_NONE), m_Diminishing(), m_combatManager(this),
+    m_threatManager(this), _aiAnimKitId(0), _movementAnimKitId(0), _meleeAnimKitId(0),
     _spellHistory(new SpellHistory(this))
 {
     m_objectType |= TYPEMASK_UNIT;
@@ -377,18 +377,12 @@ Unit::Unit(bool isWorldObject) :
     }
     m_baseSpellCritChance = 5;
 
-    m_CombatTimer = 0;
-
-    for (uint8 i = 0; i < MAX_SPELL_SCHOOL; ++i)
-        m_threatModifier[i] = 1.0f;
 
     for (uint8 i = 0; i < MAX_MOVE_TYPE; ++i)
         m_speed_rate[i] = 1.0f;
 
     m_charmInfo = nullptr;
 
-    _redirectThreadInfo = RedirectThreatInfo();
-
     // remove aurastates allowing special moves
     for (uint8 i = 0; i < MAX_REACTIVE; ++i)
         m_reactiveTimer[i] = 0;
@@ -438,28 +432,6 @@ Unit::~Unit()
     ASSERT(m_dynObj.empty());
 }
 
-// Check if unit in combat with specific unit
-bool Unit::IsInCombatWith(Unit const* who) const
-{
-    // Check target exists
-    if (!who)
-        return false;
-
-    // Search in threat list
-    ObjectGuid guid = who->GetGUID();
-    for (ThreatContainer::StorageType::const_iterator i = m_ThreatManager.getThreatList().begin(); i != m_ThreatManager.getThreatList().end(); ++i)
-    {
-        HostileReference* ref = (*i);
-
-        // Return true if the unit matches
-        if (ref && ref->getUnitGuid() == guid)
-            return true;
-    }
-
-    // Nothing found, false.
-    return false;
-}
-
 void Unit::Update(uint32 p_time)
 {
     // WARNING! Order of execution here is important, do not change.
@@ -476,24 +448,7 @@ void Unit::Update(uint32 p_time)
     // Having this would prevent spells from being proced, so let's crash
     ASSERT(!m_procDeep);
 
-    if (CanHaveThreatList() && GetThreatManager().isNeedUpdateToClient(p_time))
-        SendThreatListUpdate();
-
-    // update combat timer only for players and pets (only pets with PetAI)
-    if (IsInCombat() && (GetTypeId() == TYPEID_PLAYER || (IsPet() && IsControlledByPlayer())))
-    {
-        // Check UNIT_STATE_MELEE_ATTACKING or UNIT_STATE_CHASE (without UNIT_STATE_FOLLOW in this case) so pets can reach far away
-        // targets without stopping half way there and running off.
-        // These flags are reset after target dies or another command is given.
-        if (m_HostileRefManager.isEmpty())
-        {
-            // m_CombatTimer set at aura start and it will be freeze until aura removing
-            if (m_CombatTimer <= p_time)
-                ClearInCombat();
-            else
-                m_CombatTimer -= p_time;
-        }
-    }
+    m_combatManager.Update(p_time);
 
     // not implemented before 3.0.2
     if (uint32 base_att = getAttackTimer(BASE_ATTACK))
@@ -2060,7 +2015,7 @@ void Unit::AttackerStateUpdate(Unit* victim, WeaponAttackType attType, bool extr
     if ((attType == BASE_ATTACK || attType == OFF_ATTACK) && !IsWithinLOSInMap(victim))
         return;
 
-    CombatStart(victim);
+    AttackedTarget(victim, true);
     RemoveAurasWithInterruptFlags(SpellAuraInterruptFlags::Attacking);
 
     if (attType != BASE_ATTACK && attType != OFF_ATTACK)
@@ -2144,7 +2099,7 @@ void Unit::FakeAttackerStateUpdate(Unit* victim, WeaponAttackType attType /*= BA
     if ((attType == BASE_ATTACK || attType == OFF_ATTACK) && !IsWithinLOSInMap(victim))
         return;
 
-    CombatStart(victim);
+    AttackedTarget(victim, true);
     RemoveAurasWithInterruptFlags(SpellAuraInterruptFlags::Attacking);
 
     if (attType != BASE_ATTACK && attType != OFF_ATTACK)
@@ -5718,20 +5673,20 @@ Unit* Unit::getAttackerForHelper() const                 // If someone wants to
         return nullptr;
 
     if (Unit* victim = GetVictim())
-        if ((!IsPet() && !GetPlayerMovingMe()) || IsInCombatWith(victim) || victim->IsInCombatWith(this))
+        if ((!IsPet() && !GetPlayerMovingMe()) || IsInCombatWith(victim))
             return victim;
 
-    if (!m_attackers.empty())
-        return *(m_attackers.begin());
-
-    if (Player* owner = GetCharmerOrOwnerPlayerOrPlayerItself())
-    {
-        HostileRefManager& refs = owner->getHostileRefManager();
-        for (Reference<Unit, ThreatManager> const& ref : refs)
-            if (Unit* hostile = ref.GetSource()->GetOwner())
-                return hostile;
-    }
-
+    CombatManager const& mgr = GetCombatManager();
+    // pick arbitrary targets; our pvp combat > owner's pvp combat > our pve combat > owner's pve combat
+    Unit* owner = GetCharmerOrOwner();
+    if (mgr.HasPvPCombat())
+        return mgr.GetPvPCombatRefs().begin()->second->GetOther(this);
+    if (owner && (owner->GetCombatManager().HasPvPCombat()))
+        return owner->GetCombatManager().GetPvPCombatRefs().begin()->second->GetOther(owner);
+    if (mgr.HasPvECombat())
+        return mgr.GetPvECombatRefs().begin()->second->GetOther(this);
+    if (owner && (owner->GetCombatManager().HasPvECombat()))
+        return owner->GetCombatManager().GetPvECombatRefs().begin()->second->GetOther(owner);
     return nullptr;
 }
 
@@ -5822,19 +5777,7 @@ bool Unit::Attack(Unit* victim, bool meleeAttack)
 
     if (creature && !IsPet())
     {
-        // should not let player enter combat by right clicking target - doesn't helps
-        GetThreatManager().AddThreat(victim, 0.0f);
-        SetInCombatWith(victim);
-        if (victim->GetTypeId() == TYPEID_PLAYER)
-            victim->SetInCombatWith(this);
-
-        if (Unit* owner = victim->GetOwner())
-        {
-            GetThreatManager().AddThreat(owner, 0.0f);
-            SetInCombatWith(owner);
-            if (owner->GetTypeId() == TYPEID_PLAYER)
-                owner->SetInCombatWith(this);
-        }
+        EngageWithTarget(victim); // ensure that anything we're attacking has threat
 
         creature->SendAIReaction(AI_REACTION_HOSTILE);
         creature->CallAssistance();
@@ -5915,7 +5858,7 @@ void Unit::ValidateAttackersAndOwnTarget()
             AttackStop();
 }
 
-void Unit::CombatStop(bool includingCast)
+void Unit::CombatStop(bool includingCast, bool mutualPvP)
 {
     if (includingCast && IsNonMeleeSpellCast(false))
         InterruptNonMeleeSpells(false);
@@ -5924,19 +5867,22 @@ void Unit::CombatStop(bool includingCast)
     RemoveAllAttackers();
     if (GetTypeId() == TYPEID_PLAYER)
         ToPlayer()->SendAttackSwingCancelAttack();     // melee and ranged forced attack cancel
-    ClearInCombat();
 
-    // just in case
-    if (IsPetInCombat() && GetTypeId() != TYPEID_PLAYER)
-        ClearInPetCombat();
+    if (mutualPvP)
+        ClearInCombat();
+    else
+    { // vanish and brethren are weird
+        m_combatManager.EndAllPvECombat();
+        m_combatManager.SuppressPvPCombat();
+    }
 }
 
 void Unit::CombatStopWithPets(bool includingCast)
 {
     CombatStop(includingCast);
 
-    for (ControlList::const_iterator itr = m_Controlled.begin(); itr != m_Controlled.end(); ++itr)
-        (*itr)->CombatStop(includingCast);
+    for (Unit* minion : m_Controlled)
+        minion->CombatStop(includingCast);
 }
 
 bool Unit::isAttackingPlayer() const
@@ -6329,6 +6275,7 @@ void Unit::SetMinion(Minion *minion, bool apply)
             }
         }
     }
+    UpdatePetCombatState();
 }
 
 void Unit::GetAllMinionsByEntry(std::list<TempSummon*>& Minions, uint32 entry)
@@ -6430,6 +6377,7 @@ void Unit::SetCharm(Unit* charm, bool apply)
             m_Controlled.erase(charm);
         }
     }
+    UpdatePetCombatState();
 }
 
 void Unit::DealHeal(HealInfo& healInfo)
@@ -6576,6 +6524,8 @@ void Unit::RemoveAllControlled()
         TC_LOG_FATAL("entities.unit", "Unit %u is not able to release its minion %s", GetEntry(), GetMinionGUID().ToString().c_str());
     if (!GetCharmGUID().IsEmpty())
         TC_LOG_FATAL("entities.unit", "Unit %u is not able to release its charm %s", GetEntry(), GetCharmGUID().ToString().c_str());
+    if (!IsPet()) // pets don't use the flag for this
+        RemoveUnitFlag(UNIT_FLAG_PET_IN_COMBAT); // m_controlled is now empty, so we know none of our minions are in combat
 }
 
 bool Unit::isPossessedByPlayer() const
@@ -8143,190 +8093,119 @@ bool Unit::IsServiceProvider() const
         UNIT_NPC_FLAG_SPIRITGUIDE | UNIT_NPC_FLAG_TABARDDESIGNER | UNIT_NPC_FLAG_AUCTIONEER));
 }
 
-void Unit::SetInCombatWith(Unit* enemy)
+void Unit::EngageWithTarget(Unit* enemy)
 {
-    Unit* eOwner = enemy->GetCharmerOrOwnerOrSelf();
-    if (eOwner->IsPvP() || eOwner->IsFFAPvP())
-    {
-        SetInCombatState(true, enemy);
+    if (!enemy)
         return;
-    }
 
-    // check for duel
-    if (eOwner->GetTypeId() == TYPEID_PLAYER && eOwner->ToPlayer()->duel)
-    {
-        Unit const* myOwner = GetCharmerOrOwnerOrSelf();
-        if (((Player const*)eOwner)->duel->opponent == myOwner)
-        {
-            SetInCombatState(true, enemy);
-            return;
-        }
-    }
-    SetInCombatState(false, enemy);
-}
+    if (IsEngagedBy(enemy))
+        return;
 
-void Unit::SetImmuneToPC(bool apply, bool keepCombat)
-{
-    (void)keepCombat;
-    if (apply)
-        AddUnitFlag(UNIT_FLAG_IMMUNE_TO_PC);
+    if (CanHaveThreatList())
+        m_threatManager.AddThreat(enemy, 0.0f, nullptr, true, true);
     else
-        RemoveUnitFlag(UNIT_FLAG_IMMUNE_TO_PC);
-}
+        SetInCombatWith(enemy);
 
-void Unit::SetImmuneToNPC(bool apply, bool keepCombat)
-{
-    (void)keepCombat;
-    if (apply)
-        AddUnitFlag(UNIT_FLAG_IMMUNE_TO_NPC);
-    else
-        RemoveUnitFlag(UNIT_FLAG_IMMUNE_TO_NPC);
+    if (Creature* creature = ToCreature())
+        if (CreatureGroup* formation = creature->GetFormation())
+            formation->MemberEngagingTarget(creature, enemy);
 }
 
-void Unit::CombatStart(Unit* target, bool initialAggro)
+void Unit::AttackedTarget(Unit* target, bool canInitialAggro)
 {
-    if (initialAggro)
-    {
-        if (!target->IsStandState())
-            target->SetStandState(UNIT_STAND_STATE_STAND);
-
-        if (!target->IsInCombat() && target->GetTypeId() != TYPEID_PLAYER
-            && !target->ToCreature()->HasReactState(REACT_PASSIVE) && target->ToCreature()->IsAIEnabled)
-            target->ToCreature()->AI()->AttackStart(this);
-
-        SetInCombatWith(target);
-        target->SetInCombatWith(this);
-    }
+    if (!target->IsEngaged() && !canInitialAggro)
+        return;
+    target->EngageWithTarget(this);
+    if (Unit* targetOwner = target->GetCharmerOrOwner())
+        targetOwner->EngageWithTarget(this);
 
-    Player* me = GetCharmerOrOwnerPlayerOrPlayerItself();
-    Unit* who = target->GetCharmerOrOwnerOrSelf();
-    if (me && who->GetTypeId() == TYPEID_PLAYER)
-        me->SetContestedPvP(who->ToPlayer());
-    if (me && who->IsPvP()
-        && (who->GetTypeId() != TYPEID_PLAYER
-        || !me->duel || me->duel->opponent != who))
+    Player* myPlayerOwner = GetCharmerOrOwnerPlayerOrPlayerItself();
+    Player* targetPlayerOwner = target->GetCharmerOrOwnerPlayerOrPlayerItself();
+    if (myPlayerOwner && targetPlayerOwner && !(myPlayerOwner->duel && myPlayerOwner->duel->opponent == targetPlayerOwner))
     {
-        me->UpdatePvP(true);
-        me->RemoveAurasWithInterruptFlags(SpellAuraInterruptFlags::PvPActive);
+        myPlayerOwner->UpdatePvP(true);
+        myPlayerOwner->SetContestedPvP(targetPlayerOwner);
+        myPlayerOwner->RemoveAurasWithInterruptFlags(SpellAuraInterruptFlags::PvPActive);
     }
 }
 
-void Unit::SetInCombatState(bool PvP, Unit* enemy)
+void Unit::SetImmuneToAll(bool apply, bool keepCombat)
 {
-    // only alive units can be in combat
-    if (!IsAlive())
-        return;
-
-    if (PvP)
+    if (apply)
     {
-        m_CombatTimer = 5000;
-        if (Player* me = ToPlayer())
-            me->EnablePvpRules(true);
+        AddUnitFlag(UnitFlags(UNIT_FLAG_IMMUNE_TO_PC | UNIT_FLAG_IMMUNE_TO_NPC));
+        ValidateAttackersAndOwnTarget();
+        if (keepCombat)
+            m_threatManager.UpdateOnlineStates(true, true);
+        else
+            m_combatManager.EndAllCombat();
     }
-
-    if (IsInCombat() || HasUnitState(UNIT_STATE_EVADE))
-        return;
-
-    AddUnitFlag(UNIT_FLAG_IN_COMBAT);
-
-    if (Creature* creature = ToCreature())
+    else
     {
-        // Set home position at place of engaging combat for escorted creatures
-        if ((IsAIEnabled && creature->AI()->IsEscorted()) ||
-            GetMotionMaster()->GetCurrentMovementGeneratorType() == WAYPOINT_MOTION_TYPE ||
-            GetMotionMaster()->GetCurrentMovementGeneratorType() == POINT_MOTION_TYPE)
-            creature->SetHomePosition(GetPositionX(), GetPositionY(), GetPositionZ(), GetOrientation());
-
-        if (enemy)
-        {
-            if (IsAIEnabled)
-                creature->AI()->JustEngagedWith(enemy);
-
-            if (creature->GetFormation())
-                creature->GetFormation()->MemberEngagingTarget(creature, enemy);
-        }
-
-        if (IsPet())
-        {
-            UpdateSpeed(MOVE_RUN);
-            UpdateSpeed(MOVE_SWIM);
-            UpdateSpeed(MOVE_FLIGHT);
-        }
-
-        if (!(creature->GetCreatureTemplate()->type_flags & CREATURE_TYPE_FLAG_MOUNTED_COMBAT_ALLOWED))
-            Dismount();
+        RemoveUnitFlag(UnitFlags(UNIT_FLAG_IMMUNE_TO_PC | UNIT_FLAG_IMMUNE_TO_NPC));
+        m_threatManager.UpdateOnlineStates(true, true);
     }
+}
 
-    for (Unit::ControlList::iterator itr = m_Controlled.begin(); itr != m_Controlled.end();)
+void Unit::SetImmuneToPC(bool apply, bool keepCombat)
+{
+    if (apply)
     {
-        Unit* controlled = *itr;
-        ++itr;
-
-        controlled->SetInCombatState(PvP, enemy);
+        AddUnitFlag(UNIT_FLAG_IMMUNE_TO_PC);
+        ValidateAttackersAndOwnTarget();
+        if (keepCombat)
+            m_threatManager.UpdateOnlineStates(true, true);
+        else
+        {
+            std::list<CombatReference*> toEnd;
+            for (auto const& pair : m_combatManager.GetPvECombatRefs())
+                if (pair.second->GetOther(this)->HasUnitFlag(UNIT_FLAG_PVP_ATTACKABLE))
+                    toEnd.push_back(pair.second);
+            for (auto const& pair : m_combatManager.GetPvPCombatRefs())
+                if (pair.second->GetOther(this)->HasUnitFlag(UNIT_FLAG_PVP_ATTACKABLE))
+                    toEnd.push_back(pair.second);
+            for (CombatReference* ref : toEnd)
+                ref->EndCombat();
+        }
     }
-
-    for (auto itr = m_appliedAuras.begin(); itr != m_appliedAuras.end();)
+    else
     {
-        AuraApplication* aurApp = itr->second;
-        ++itr;
-
-        aurApp->GetBase()->CallScriptEnterLeaveCombatHandlers(aurApp, true);
+        RemoveUnitFlag(UNIT_FLAG_IMMUNE_TO_PC);
+        m_threatManager.UpdateOnlineStates(true, true);
     }
-
-    if (Spell* spell = m_currentSpells[CURRENT_GENERIC_SPELL])
-        if (spell->getState() == SPELL_STATE_PREPARING
-            && spell->m_spellInfo->HasAttribute(SPELL_ATTR0_CANT_USED_IN_COMBAT)
-            && spell->m_spellInfo->InterruptFlags.HasFlag(SpellInterruptFlags::Combat))
-            InterruptNonMeleeSpells(false);
-
-    RemoveAurasWithInterruptFlags(SpellAuraInterruptFlags::EnteringCombat);
-    ProcSkillsAndAuras(enemy, PROC_FLAG_ENTER_COMBAT, PROC_FLAG_NONE, PROC_SPELL_TYPE_MASK_ALL, PROC_SPELL_PHASE_NONE, PROC_HIT_NONE, nullptr, nullptr, nullptr);
 }
 
-void Unit::ClearInCombat()
+void Unit::SetImmuneToNPC(bool apply, bool keepCombat)
 {
-    m_CombatTimer = 0;
-    RemoveUnitFlag(UNIT_FLAG_IN_COMBAT);
-
-    // Player's state will be cleared in Player::UpdateContestedPvP
-    if (Creature* creature = ToCreature())
+    if (apply)
     {
-        ClearUnitState(UNIT_STATE_ATTACK_PLAYER);
-        if (HasDynamicFlag(UNIT_DYNFLAG_TAPPED))
-            SetDynamicFlags(creature->GetCreatureTemplate()->dynamicflags);
-
-        if (creature->IsPet() || creature->IsGuardian())
+        AddUnitFlag(UNIT_FLAG_IMMUNE_TO_NPC);
+        ValidateAttackersAndOwnTarget();
+        if (keepCombat)
+            m_threatManager.UpdateOnlineStates(true, true);
+        else
         {
-            if (Unit* owner = GetOwner())
-                for (uint8 i = 0; i < MAX_MOVE_TYPE; ++i)
-                    if (owner->GetSpeedRate(UnitMoveType(i)) > GetSpeedRate(UnitMoveType(i)))
-                        SetSpeedRate(UnitMoveType(i), owner->GetSpeedRate(UnitMoveType(i)));
+            std::list<CombatReference*> toEnd;
+            for (auto const& pair : m_combatManager.GetPvECombatRefs())
+                if (!pair.second->GetOther(this)->HasUnitFlag(UNIT_FLAG_PVP_ATTACKABLE))
+                    toEnd.push_back(pair.second);
+            for (auto const& pair : m_combatManager.GetPvPCombatRefs())
+                if (!pair.second->GetOther(this)->HasUnitFlag(UNIT_FLAG_PVP_ATTACKABLE))
+                    toEnd.push_back(pair.second);
+            for (CombatReference* ref : toEnd)
+                ref->EndCombat();
         }
-        else if (!IsCharmed())
-            return;
     }
-
-    OnCombatExit();
-
-    RemoveAurasWithInterruptFlags(SpellAuraInterruptFlags::LeavingCombat);
+    else
+    {
+        RemoveUnitFlag(UNIT_FLAG_IMMUNE_TO_NPC);
+        m_threatManager.UpdateOnlineStates(true, true);
+    }
 }
 
-void Unit::ClearInPetCombat()
+bool Unit::IsThreatened() const
 {
-    RemoveUnitFlag(UNIT_FLAG_PET_IN_COMBAT);
-    if (Unit* owner = GetOwner())
-        owner->RemoveUnitFlag(UNIT_FLAG_PET_IN_COMBAT);
-}
-
-void Unit::OnCombatExit()
-{
-    for (auto itr = m_appliedAuras.begin(); itr != m_appliedAuras.end();)
-    {
-        AuraApplication* aurApp = itr->second;
-        ++itr;
-
-        aurApp->GetBase()->CallScriptEnterLeaveCombatHandlers(aurApp, false);
-    }
+    return !m_threatManager.IsThreatListEmpty();
 }
 
 bool Unit::isTargetableForAttack(bool checkFakeDeath) const
@@ -8375,7 +8254,7 @@ bool Unit::_IsValidAttackTarget(Unit const* target, SpellInfo const* bySpell, Wo
             {
                 // ignore stealth for aoe spells. Ignore stealth if target is player and unit in combat with same player
                 bool const ignoreStealthCheck = (bySpell && bySpell->IsAffectingArea()) ||
-                    (target->GetTypeId() == TYPEID_PLAYER && target->HasStealthAura() && target->IsInCombat() && IsInCombatWith(target));
+                    (target->GetTypeId() == TYPEID_PLAYER && target->HasStealthAura() && IsInCombatWith(target));
 
                 if (!CanSeeOrDetect(target, ignoreStealthCheck))
                     return false;
@@ -8961,7 +8840,6 @@ void Unit::setDeathState(DeathState s)
     {
         CombatStop();
         GetThreatManager().ClearAllThreat();
-        getHostileRefManager().deleteReferences();
 
         if (IsNonMeleeSpellCast(false))
             InterruptNonMeleeSpells(false);
@@ -9005,243 +8883,60 @@ void Unit::setDeathState(DeathState s)
         RemoveUnitFlag(UNIT_FLAG_SKINNABLE); // clear skinnable for creature and player (at battleground)
 }
 
-/*########################################
-########                          ########
-########       AGGRO SYSTEM       ########
-########                          ########
-########################################*/
-bool Unit::CanHaveThreatList(bool skipAliveCheck) const
-{
-    // only creatures can have threat list
-    if (GetTypeId() != TYPEID_UNIT)
-        return false;
-
-    // only alive units can have threat list
-    if (!skipAliveCheck && !IsAlive())
-        return false;
-
-    // totems can not have threat list
-    if (IsTotem())
-        return false;
-
-    // vehicles can not have threat list
-    //if (ToCreature()->IsVehicle())
-    //    return false;
-
-    // summons can not have a threat list, unless they are controlled by a creature
-    if (HasUnitTypeMask(UNIT_MASK_MINION | UNIT_MASK_GUARDIAN | UNIT_MASK_CONTROLABLE_GUARDIAN) && GetOwnerGUID().IsPlayer())
-        return false;
-
-    return true;
-}
-
-//======================================================================
-
-float Unit::ApplyTotalThreatModifier(float fThreat, SpellSchoolMask schoolMask)
-{
-    if (!HasAuraType(SPELL_AURA_MOD_THREAT) || fThreat < 0)
-        return fThreat;
-
-    SpellSchools school = GetFirstSchoolInMask(schoolMask);
-
-    return fThreat * m_threatModifier[school];
-}
-
 //======================================================================
 
-void Unit::TauntApply(Unit* taunter)
+void Unit::AtEnterCombat()
 {
-    ASSERT(GetTypeId() == TYPEID_UNIT);
-
-    if (!taunter || (taunter->GetTypeId() == TYPEID_PLAYER && taunter->ToPlayer()->IsGameMaster()))
-        return;
-
-    if (!CanHaveThreatList())
-        return;
-
-    Creature* creature = ToCreature();
-
-    if (creature->HasReactState(REACT_PASSIVE))
-        return;
+    for (auto itr = m_appliedAuras.begin(); itr != m_appliedAuras.end();)
+    {
+        AuraApplication* aurApp = itr->second;
+        ++itr;
 
-    Unit* target = GetVictim();
-    if (target && target == taunter)
-        return;
+        aurApp->GetBase()->CallScriptEnterLeaveCombatHandlers(aurApp, true);
+    }
 
-    if (!IsFocusing(nullptr, true))
-        SetInFront(taunter);
-    if (creature->IsAIEnabled)
-        creature->AI()->AttackStart(taunter);
+    if (Spell* spell = m_currentSpells[CURRENT_GENERIC_SPELL])
+        if (spell->getState() == SPELL_STATE_PREPARING
+            && spell->m_spellInfo->HasAttribute(SPELL_ATTR0_CANT_USED_IN_COMBAT)
+            && spell->m_spellInfo->InterruptFlags.HasFlag(SpellInterruptFlags::Combat))
+            InterruptNonMeleeSpells(false);
 
-    //m_ThreatManager.tauntApply(taunter);
+    RemoveAurasWithInterruptFlags(SpellAuraInterruptFlags::EnteringCombat);
+    ProcSkillsAndAuras(nullptr, PROC_FLAG_ENTER_COMBAT, PROC_FLAG_NONE, PROC_SPELL_TYPE_MASK_ALL, PROC_SPELL_PHASE_NONE, PROC_HIT_NONE, nullptr, nullptr, nullptr);
 }
 
-//======================================================================
-
-void Unit::TauntFadeOut(Unit* taunter)
+void Unit::AtExitCombat()
 {
-    ASSERT(GetTypeId() == TYPEID_UNIT);
-
-    if (!taunter || (taunter->GetTypeId() == TYPEID_PLAYER && taunter->ToPlayer()->IsGameMaster()))
-        return;
-
-    if (!CanHaveThreatList())
-        return;
-
-    Creature* creature = ToCreature();
-
-    if (creature->HasReactState(REACT_PASSIVE))
-        return;
-
-    Unit* target = GetVictim();
-    if (!target || target != taunter)
-        return;
-
-    if (m_ThreatManager.isThreatListEmpty())
+    for (auto itr = m_appliedAuras.begin(); itr != m_appliedAuras.end();)
     {
-        if (creature->IsAIEnabled)
-            creature->AI()->EnterEvadeMode(CreatureAI::EVADE_REASON_NO_HOSTILES);
-        return;
-    }
-
-    target = creature->SelectVictim();  // might have more taunt auras remaining
+        AuraApplication* aurApp = itr->second;
+        ++itr;
 
-    if (target && target != taunter)
-    {
-        if (!IsFocusing(nullptr, true))
-            SetInFront(target);
-        if (creature->IsAIEnabled)
-            creature->AI()->AttackStart(target);
+        aurApp->GetBase()->CallScriptEnterLeaveCombatHandlers(aurApp, false);
     }
-}
 
-//======================================================================
+    RemoveAurasWithInterruptFlags(SpellAuraInterruptFlags::LeavingCombat);
+}
 
-Unit* Creature::SelectVictim()
+void Unit::UpdatePetCombatState()
 {
-    // function provides main threat functionality
-    // next-victim-selection algorithm and evade mode are called
-    // threat list sorting etc.
+    ASSERT(!IsPet()); // player pets do not use UNIT_FLAG_PET_IN_COMBAT for this purpose - but player pets should also never have minions of their own to call this
 
-    Unit* target = nullptr;
-    // First checking if we have some taunt on us
-    AuraEffectList const& tauntAuras = GetAuraEffectsByType(SPELL_AURA_MOD_TAUNT);
-    if (!tauntAuras.empty())
-    {
-        Unit* caster = tauntAuras.back()->GetCaster();
-
-        // The last taunt aura caster is alive an we are happy to attack him
-        if (caster && caster->IsAlive())
-            return GetVictim();
-        else if (tauntAuras.size() > 1)
+    bool state = false;
+    for (Unit* minion : m_Controlled)
+        if (minion->IsInCombat())
         {
-            // We do not have last taunt aura caster but we have more taunt auras,
-            // so find first available target
-
-            // Auras are pushed_back, last caster will be on the end
-            AuraEffectList::const_iterator aura = --tauntAuras.end();
-            do
-            {
-                --aura;
-                caster = (*aura)->GetCaster();
-                if (caster && CanSeeOrDetect(caster, true) && IsValidAttackTarget(caster) && caster->isInAccessiblePlaceFor(ToCreature()))
-                {
-                    target = caster;
-                    break;
-                }
-            } while (aura != tauntAuras.begin());
+            state = true;
+            break;
         }
-        else
-            target = GetVictim();
-    }
 
-    if (CanHaveThreatList())
-    {
-        if (!target && !m_ThreatManager.isThreatListEmpty())
-            // No taunt aura or taunt aura caster is dead standard target selection
-            target = m_ThreatManager.getHostilTarget();
-    }
-    else if (!HasReactState(REACT_PASSIVE))
-    {
-        // We have player pet probably
-        target = getAttackerForHelper();
-        if (!target && IsSummon())
-        {
-            if (Unit* owner = ToTempSummon()->GetOwner())
-            {
-                if (owner->IsInCombat())
-                    target = owner->getAttackerForHelper();
-                if (!target)
-                {
-                    for (ControlList::const_iterator itr = owner->m_Controlled.begin(); itr != owner->m_Controlled.end(); ++itr)
-                    {
-                        if ((*itr)->IsInCombat())
-                        {
-                            target = (*itr)->getAttackerForHelper();
-                            if (target)
-                                break;
-                        }
-                    }
-                }
-            }
-        }
-    }
+    if (state)
+        AddUnitFlag(UNIT_FLAG_PET_IN_COMBAT);
     else
-        return nullptr;
-
-    if (target && _IsTargetAcceptable(target) && CanCreatureAttack(target))
-    {
-        if (!IsFocusing(nullptr, true))
-            SetInFront(target);
-        return target;
-    }
-
-    // last case when creature must not go to evade mode:
-    // it in combat but attacker not make any damage and not enter to aggro radius to have record in threat list
-    // Note: creature does not have targeted movement generator but has attacker in this case
-    for (AttackerSet::const_iterator itr = m_attackers.begin(); itr != m_attackers.end(); ++itr)
-    {
-        if ((*itr) && CanCreatureAttack(*itr) && (*itr)->GetTypeId() != TYPEID_PLAYER
-        && !(*itr)->ToCreature()->HasUnitTypeMask(UNIT_MASK_CONTROLABLE_GUARDIAN))
-            return nullptr;
-    }
-
-    /// @todo a vehicle may eat some mob, so mob should not evade
-    if (GetVehicle())
-        return nullptr;
-
-    // search nearby enemy before enter evade mode
-    if (HasReactState(REACT_AGGRESSIVE))
-    {
-        target = SelectNearestTargetInAttackDistance(m_CombatDistance ? m_CombatDistance : ATTACK_DISTANCE);
-
-        if (target && _IsTargetAcceptable(target) && CanCreatureAttack(target))
-            return target;
-    }
-
-    Unit::AuraEffectList const& iAuras = GetAuraEffectsByType(SPELL_AURA_MOD_INVISIBILITY);
-    if (!iAuras.empty())
-    {
-        for (Unit::AuraEffectList::const_iterator itr = iAuras.begin(); itr != iAuras.end(); ++itr)
-        {
-            if ((*itr)->GetBase()->IsPermanent())
-            {
-                AI()->EnterEvadeMode(CreatureAI::EVADE_REASON_OTHER);
-                break;
-            }
-        }
-        return nullptr;
-    }
-
-    // enter in evade mode in other case
-    AI()->EnterEvadeMode(CreatureAI::EVADE_REASON_NO_HOSTILES);
-
-    return nullptr;
+        RemoveUnitFlag(UNIT_FLAG_PET_IN_COMBAT);
 }
 
 //======================================================================
-//======================================================================
-//======================================================================
 
 float Unit::ApplyEffectModifiers(SpellInfo const* spellProto, uint8 effect_index, float value) const
 {
@@ -10274,7 +9969,6 @@ void Unit::CleanupBeforeRemoveFromMap(bool finalCleanup)
     m_Events.KillAllEvents(false);                      // non-delatable (currently cast spells) will not deleted now but it will deleted at call in Map::RemoveAllObjectsInRemoveList
     CombatStop();
     GetThreatManager().ClearAllThreat();
-    getHostileRefManager().deleteReferences();
 }
 
 void Unit::CleanupsBeforeDelete(bool finalCleanup)
@@ -11701,7 +11395,6 @@ void Unit::Kill(Unit* victim, bool durabilityLoss /*= true*/, bool skipSettingDe
     }
 
     // 10% durability loss on death
-    // clean InHateListOf
     if (Player* plrVictim = victim->ToPlayer())
     {
         // remember victim PvP death for corpse type and corpse reclaim delay
@@ -12107,7 +11800,6 @@ bool Unit::SetCharmedBy(Unit* charmer, CharmType type, AuraApplication const* au
 
     CastStop();
     CombatStop(); /// @todo CombatStop(true) may cause crash (interrupt spells)
-    GetThreatManager().ClearAllThreat();
 
     Player* playerCharmer = charmer->ToPlayer();
 
@@ -12255,8 +11947,6 @@ void Unit::RemoveCharmedBy(Unit* charmer)
 
     CastStop();
     CombatStop(); /// @todo CombatStop(true) may cause crash (interrupt spells)
-    getHostileRefManager().deleteReferences();
-    GetThreatManager().ClearAllThreat();
 
     if (_oldFactionId)
     {
@@ -12336,6 +12026,8 @@ void Unit::RemoveCharmedBy(Unit* charmer)
         player->SetClientControl(this, true);
     }
 
+    EngageWithTarget(charmer);
+
     // a guardian should always have charminfo
     if (playerCharmer && this != charmer->GetFirstControlled())
         playerCharmer->SendRemoveControlBar();
@@ -12363,11 +12055,6 @@ void Unit::RestoreFaction()
     }
 }
 
-Unit* Unit::GetRedirectThreatTarget()
-{
-    return !_redirectThreadInfo.GetTargetGUID().IsEmpty() ? ObjectAccessor::GetUnit(*this, _redirectThreadInfo.GetTargetGUID()) : nullptr;
-}
-
 bool Unit::CreateVehicleKit(uint32 id, uint32 creatureEntry, bool loading /*= false*/)
 {
     VehicleEntry const* vehInfo = sVehicleStore.LookupEntry(id);
@@ -12748,35 +12435,7 @@ void Unit::OnPhaseChange()
         return;
 
     if (GetTypeId() == TYPEID_UNIT || !ToPlayer()->GetSession()->PlayerLogout())
-    {
-        HostileRefManager& refManager = getHostileRefManager();
-        HostileReference* ref = refManager.getFirst();
-
-        while (ref)
-        {
-            if (Unit* unit = ref->GetSource()->GetOwner())
-                if (Creature* creature = unit->ToCreature())
-                    refManager.setOnlineOfflineState(creature, creature->IsInPhase(this));
-
-            ref = ref->next();
-        }
-
-        // modify threat lists for new phasemask
-        if (GetTypeId() != TYPEID_PLAYER)
-        {
-            std::list<HostileReference*> threatList = GetThreatManager().getThreatList();
-            std::list<HostileReference*> offlineThreatList = GetThreatManager().getOfflineThreatList();
-
-            // merge expects sorted lists
-            threatList.sort();
-            offlineThreatList.sort();
-            threatList.merge(offlineThreatList);
-
-            for (std::list<HostileReference*>::const_iterator itr = threatList.begin(); itr != threatList.end(); ++itr)
-                if (Unit* unit = (*itr)->getTarget())
-                    unit->getHostileRefManager().setOnlineOfflineState(ToCreature(), unit->IsInPhase(this));
-        }
-    }
+        m_threatManager.UpdateOnlineStates(true, true);
 }
 
 void Unit::UpdateObjectVisibility(bool forced)
@@ -12785,6 +12444,7 @@ void Unit::UpdateObjectVisibility(bool forced)
         AddToNotify(NOTIFY_VISIBILITY_CHANGED);
     else
     {
+        m_threatManager.UpdateOnlineStates(true, true);
         WorldObject::UpdateObjectVisibility(true);
         // call MoveInLineOfSight for nearby creatures
         Trinity::AIRelocationNotifier notifier(*this);
@@ -13222,7 +12882,9 @@ bool Unit::CanSwim() const
         return true;
     if (HasUnitFlag2(UnitFlags2(0x1000000)))
         return false;
-    return HasUnitFlag(UnitFlags(UNIT_FLAG_PET_IN_COMBAT | UNIT_FLAG_RENAME | UNIT_FLAG_UNK_15));
+    if (IsPet() && HasUnitFlag(UNIT_FLAG_PET_IN_COMBAT))
+        return true;
+    return HasUnitFlag(UnitFlags(UNIT_FLAG_RENAME | UNIT_FLAG_UNK_15));
 }
 
 void Unit::NearTeleportTo(Position const& pos, bool casting /*= false*/)
@@ -13344,60 +13006,6 @@ void Unit::UpdateHeight(float newZ)
         GetVehicleKit()->RelocatePassengers();
 }
 
-void Unit::SendThreatListUpdate()
-{
-    if (!GetThreatManager().isThreatListEmpty())
-    {
-        WorldPackets::Combat::ThreatUpdate packet;
-        packet.UnitGUID = GetGUID();
-        ThreatContainer::StorageType const& tlist = GetThreatManager().getThreatList();
-        packet.ThreatList.reserve(tlist.size());
-        for (ThreatContainer::StorageType::const_iterator itr = tlist.begin(); itr != tlist.end(); ++itr)
-        {
-            WorldPackets::Combat::ThreatInfo info;
-            info.UnitGUID = (*itr)->getUnitGuid();
-            info.Threat = int64((*itr)->getThreat() * 100);
-            packet.ThreatList.push_back(info);
-        }
-        SendMessageToSet(packet.Write(), false);
-    }
-}
-
-void Unit::SendChangeCurrentVictimOpcode(HostileReference* pHostileReference)
-{
-    if (!GetThreatManager().isThreatListEmpty())
-    {
-        WorldPackets::Combat::HighestThreatUpdate packet;
-        packet.UnitGUID = GetGUID();
-        packet.HighestThreatGUID = pHostileReference->getUnitGuid();
-        ThreatContainer::StorageType const& tlist = GetThreatManager().getThreatList();
-        packet.ThreatList.reserve(tlist.size());
-        for (ThreatContainer::StorageType::const_iterator itr = tlist.begin(); itr != tlist.end(); ++itr)
-        {
-            WorldPackets::Combat::ThreatInfo info;
-            info.UnitGUID = (*itr)->getUnitGuid();
-            info.Threat = int64((*itr)->getThreat() * 100);
-            packet.ThreatList.push_back(info);
-        }
-        SendMessageToSet(packet.Write(), false);
-    }
-}
-
-void Unit::SendClearThreatListOpcode()
-{
-    WorldPackets::Combat::ThreatClear packet;
-    packet.UnitGUID = GetGUID();
-    SendMessageToSet(packet.Write(), false);
-}
-
-void Unit::SendRemoveFromThreatListOpcode(HostileReference* pHostileReference)
-{
-    WorldPackets::Combat::ThreatRemove packet;
-    packet.UnitGUID = GetGUID();
-    packet.AboutGUID = pHostileReference->getUnitGuid();
-    SendMessageToSet(packet.Write(), false);
-}
-
 // baseRage means damage taken when attacker = false
 void Unit::RewardRage(uint32 baseRage)
 {
@@ -13439,10 +13047,15 @@ void Unit::StopAttackFaction(uint32 faction_id)
             ++itr;
     }
 
-    getHostileRefManager().deleteReferencesForFaction(faction_id);
+    std::vector<CombatReference*> refsToEnd;
+    for (auto const& pair : m_combatManager.GetPvECombatRefs())
+        if (pair.second->GetOther(this)->GetFactionTemplateEntry()->Faction == faction_id)
+            refsToEnd.push_back(pair.second);
+    for (CombatReference* ref : refsToEnd)
+        ref->EndCombat();
 
-    for (ControlList::const_iterator itr = m_Controlled.begin(); itr != m_Controlled.end(); ++itr)
-            (*itr)->StopAttackFaction(faction_id);
+    for (Unit* minion : m_Controlled)
+        minion->StopAttackFaction(faction_id);
 }
 
 void Unit::OutDebugInfo() const
diff --git a/src/server/game/Entities/Unit/Unit.h b/src/server/game/Entities/Unit/Unit.h
index 5275677e2e8..7f5f57a621f 100644
--- a/src/server/game/Entities/Unit/Unit.h
+++ b/src/server/game/Entities/Unit/Unit.h
@@ -22,7 +22,7 @@
 #include "EventProcessor.h"
 #include "FollowerReference.h"
 #include "FollowerRefManager.h"
-#include "HostileRefManager.h"
+#include "CombatManager.h"
 #include "OptionalFwd.h"
 #include "SpellAuraDefines.h"
 #include "SpellDefines.h"
@@ -581,28 +581,6 @@ struct SpellPeriodicAuraLogInfo
 
 uint32 createProcHitMask(SpellNonMeleeDamage* damageInfo, SpellMissInfo missCondition);
 
-struct RedirectThreatInfo
-{
-    RedirectThreatInfo() : _threatPct(0) { }
-    ObjectGuid _targetGUID;
-    uint32 _threatPct;
-
-    ObjectGuid GetTargetGUID() const { return _targetGUID; }
-    uint32 GetThreatPct() const { return _threatPct; }
-
-    void Set(ObjectGuid guid, uint32 pct)
-    {
-        _targetGUID = guid;
-        _threatPct = pct;
-    }
-
-    void ModifyThreatPct(int32 amount)
-    {
-        amount += _threatPct;
-        _threatPct = uint32(std::max(0, amount));
-    }
-};
-
 enum CurrentSpellTypes : uint8
 {
     CURRENT_MELEE_SPELL             = 0,
@@ -854,7 +832,7 @@ class TC_GAME_API Unit : public WorldObject
         }
 
         void ValidateAttackersAndOwnTarget();
-        void CombatStop(bool includingCast = false);
+        void CombatStop(bool includingCast = false, bool mutualPvP = true);
         void CombatStopWithPets(bool includingCast = false);
         void StopAttackFaction(uint32 faction_id);
         Unit* SelectNearbyTarget(Unit* exclude = nullptr, float dist = NOMINAL_MELEE_RANGE) const;
@@ -1123,29 +1101,45 @@ class TC_GAME_API Unit : public WorldObject
 
         bool IsInFlight()  const { return HasUnitState(UNIT_STATE_IN_FLIGHT); }
 
-        bool IsEngaged() const { return IsInCombat(); }
-        bool IsEngagedBy(Unit const* who) const { return IsInCombatWith(who); }
-        void EngageWithTarget(Unit* who) { SetInCombatWith(who); who->SetInCombatWith(this); GetThreatManager().AddThreat(who, 0.0f); }
-        bool IsThreatened() const { return CanHaveThreatList() && !GetThreatManager().IsThreatListEmpty(); }
-        bool IsThreatenedBy(Unit const* who) const { return who && CanHaveThreatList() && GetThreatManager().IsThreatenedBy(who); }
+        /// ====================== THREAT & COMBAT ====================
+        bool CanHaveThreatList() const { return m_threatManager.CanHaveThreatList(); }
+        // For NPCs with threat list: Whether there are any enemies on our threat list
+        // For other units: Whether we're in combat
+        // This value is different from IsInCombat when a projectile spell is midair (combat on launch - threat+aggro on impact)
+        bool IsEngaged() const { return CanHaveThreatList() ? m_threatManager.IsEngaged() : IsInCombat(); }
+        bool IsEngagedBy(Unit const* who) const { return CanHaveThreatList() ? IsThreatenedBy(who) : IsInCombatWith(who); }
+        void EngageWithTarget(Unit* who); // Adds target to threat list if applicable, otherwise just sets combat state
+        // Combat handling
+        CombatManager& GetCombatManager() { return m_combatManager; }
+        CombatManager const& GetCombatManager() const { return m_combatManager; }
+        void AttackedTarget(Unit* target, bool canInitialAggro);
 
-        void SetImmuneToAll(bool apply, bool keepCombat = false) { SetImmuneToPC(apply, keepCombat); SetImmuneToNPC(apply, keepCombat); }
         bool IsImmuneToAll() const { return IsImmuneToPC() && IsImmuneToNPC(); }
-        void SetImmuneToPC(bool apply, bool keepCombat = false);
+        void SetImmuneToAll(bool apply, bool keepCombat);
+        virtual void SetImmuneToAll(bool apply) { SetImmuneToAll(apply, false); }
         bool IsImmuneToPC() const { return HasUnitFlag(UNIT_FLAG_IMMUNE_TO_PC); }
-        void SetImmuneToNPC(bool apply, bool keepCombat = false);
+        void SetImmuneToPC(bool apply, bool keepCombat);
+        virtual void SetImmuneToPC(bool apply) { SetImmuneToPC(apply, false); }
         bool IsImmuneToNPC() const { return HasUnitFlag(UNIT_FLAG_IMMUNE_TO_NPC); }
+        void SetImmuneToNPC(bool apply, bool keepCombat);
+        virtual void SetImmuneToNPC(bool apply) { SetImmuneToNPC(apply, false); }
+
+        bool IsInCombat() const { return HasUnitFlag(UNIT_FLAG_IN_COMBAT); }
+        bool IsInCombatWith(Unit const* who) const { return who && m_combatManager.IsInCombatWith(who); }
+        void SetInCombatWith(Unit* enemy) { if (enemy) m_combatManager.SetInCombatWith(enemy); }
+        void ClearInCombat() { m_combatManager.EndAllCombat(); }
+        void UpdatePetCombatState();
+        // Threat handling
+        bool IsThreatened() const;
+        bool IsThreatenedBy(Unit const* who) const { return who && m_threatManager.IsThreatenedBy(who, true); }
+        // Exposes the threat manager directly - be careful when interfacing with this
+        // As a general rule of thumb, any unit pointer MUST be null checked BEFORE passing it to threatmanager methods
+        // threatmanager will NOT null check your pointers for you - misuse = crash
+        ThreatManager& GetThreatManager() { return m_threatManager; }
+        ThreatManager const& GetThreatManager() const { return m_threatManager; }
 
-        bool IsInCombat()  const { return HasUnitFlag(UNIT_FLAG_IN_COMBAT); }
-        bool IsPetInCombat() const { return HasUnitFlag(UNIT_FLAG_PET_IN_COMBAT); }
-        bool IsInCombatWith(Unit const* who) const;
-        void CombatStart(Unit* target, bool initialAggro = true);
-        void SetInCombatState(bool PvP, Unit* enemy = nullptr);
-        void SetInCombatWith(Unit* enemy);
-        void ClearInCombat();
-        void ClearInPetCombat();
-        uint32 GetCombatTimer() const { return m_CombatTimer; }
-        virtual void OnCombatExit();
+        void SendClearTarget();
+        void SendThreatListUpdate() { m_threatManager.SendThreatListToClients(); }
 
         bool HasAuraTypeWithFamilyFlags(AuraType auraType, uint32 familyName, flag128 familyFlags) const;
         bool virtual HasSpell(uint32 /*spellID*/) const { return false; }
@@ -1251,13 +1245,6 @@ class TC_GAME_API Unit : public WorldObject
         void SetFacingTo(float const ori, bool force = true);
         void SetFacingToObject(WorldObject const* object, bool force = true);
 
-        void SendChangeCurrentVictimOpcode(HostileReference* pHostileReference);
-        void SendClearThreatListOpcode();
-        void SendRemoveFromThreatListOpcode(HostileReference* pHostileReference);
-        void SendThreatListUpdate();
-
-        void SendClearTarget();
-
         bool IsAlive() const { return (m_deathState == ALIVE); }
         bool isDying() const { return (m_deathState == JUST_DIED); }
         bool isDead() const { return (m_deathState == DEAD || m_deathState == CORPSE); }
@@ -1554,7 +1541,6 @@ class TC_GAME_API Unit : public WorldObject
         float m_modSpellHitChance;
         int32 m_baseSpellCritChance;
 
-        float m_threatModifier[MAX_SPELL_SCHOOL];
 
         uint32 m_baseAttackSpeed[MAX_ATTACK];
         float m_modAttackSpeedPct[MAX_ATTACK];
@@ -1632,17 +1618,6 @@ class TC_GAME_API Unit : public WorldObject
         SpellImmuneContainer m_spellImmune[MAX_SPELL_IMMUNITY];
         uint32 m_lastSanctuaryTime;
 
-        // Threat related methods
-        bool CanHaveThreatList(bool skipAliveCheck = false) const;
-        float ApplyTotalThreatModifier(float fThreat, SpellSchoolMask schoolMask = SPELL_SCHOOL_MASK_NORMAL);
-        void TauntApply(Unit* victim);
-        void TauntFadeOut(Unit* taunter);
-        ThreatManager& GetThreatManager() { return m_ThreatManager; }
-        ThreatManager const& GetThreatManager() const { return m_ThreatManager; }
-        void addHatedBy(HostileReference* pHostileReference) { m_HostileRefManager.insertFirst(pHostileReference); }
-        void removeHatedBy(HostileReference* /*pHostileReference*/) { /* nothing to do yet */ }
-        HostileRefManager& getHostileRefManager() { return m_HostileRefManager; }
-
         VisibleAuraContainer const& GetVisibleAuras() const { return m_visibleAuras; }
         bool HasVisibleAura(AuraApplication* aurApp) const { return m_visibleAuras.count(aurApp) > 0; }
         void SetVisibleAura(AuraApplication* aurApp);
@@ -1724,8 +1699,6 @@ class TC_GAME_API Unit : public WorldObject
         uint32 SpellCriticalDamageBonus(SpellInfo const* spellProto, uint32 damage, Unit* victim);
         uint32 SpellCriticalHealingBonus(SpellInfo const* spellProto, uint32 damage, Unit* victim);
 
-        void SetContestedPvP(Player* attackedPlayer = nullptr);
-
         uint32 GetCastingTimeForBonus(SpellInfo const* spellProto, DamageEffectType damagetype, uint32 CastingTime) const;
         float CalculateDefaultCoefficient(SpellInfo const* spellInfo, DamageEffectType damagetype) const;
 
@@ -1810,13 +1783,6 @@ class TC_GAME_API Unit : public WorldObject
 
         uint32 GetModelForForm(ShapeshiftForm form, uint32 spellId) const;
 
-        // Redirect Threat
-        void SetRedirectThreat(ObjectGuid guid, uint32 pct) { _redirectThreadInfo.Set(guid, pct); }
-        void ResetRedirectThreat() { SetRedirectThreat(ObjectGuid::Empty, 0); }
-        void ModifyRedirectThreat(int32 amount) { _redirectThreadInfo.ModifyThreatPct(amount); }
-        uint32 GetRedirectThreatPercent() const { return _redirectThreadInfo.GetThreatPct(); }
-        Unit* GetRedirectThreatTarget();
-
         friend class VehicleJoinEvent;
         bool IsAIEnabled, NeedChangeAI;
         ObjectGuid LastCharmerGUID;
@@ -1977,8 +1943,6 @@ class TC_GAME_API Unit : public WorldObject
         uint32 m_reactiveTimer[MAX_REACTIVE];
         uint32 m_regenTimer;
 
-        ThreatManager m_ThreatManager;
-
         Vehicle* m_vehicle;
         Vehicle* m_vehicleKit;
 
@@ -1994,6 +1958,9 @@ class TC_GAME_API Unit : public WorldObject
         virtual void ProcessTerrainStatusUpdate(ZLiquidStatus status, Optional<LiquidData> const& liquidData);
         virtual void SetInWater(bool inWater);
 
+        virtual void AtEnterCombat();
+        virtual void AtExitCombat();
+
     private:
 
         void UpdateSplineMovement(uint32 t_diff);
@@ -2016,17 +1983,17 @@ class TC_GAME_API Unit : public WorldObject
     private:
 
         uint32 m_state;                                     // Even derived shouldn't modify
-        uint32 m_CombatTimer;
         TimeTrackerSmall m_movesplineTimer;
 
         Diminishing m_Diminishing;
         // Manage all Units that are threatened by us
-        HostileRefManager m_HostileRefManager;
+        friend class CombatManager;
+        CombatManager m_combatManager;
+        friend class ThreatManager;
+        ThreatManager m_threatManager;
 
         FollowerRefManager m_FollowingRefManager;
 
-        RedirectThreatInfo _redirectThreadInfo;
-
         bool m_cleanupDone; // lock made to not add stuff after cleanup before delete
         bool m_duringRemoveFromWorld; // lock made to not add stuff after begining removing from world
         bool _instantCast;
diff --git a/src/server/game/Grids/ObjectGridLoader.cpp b/src/server/game/Grids/ObjectGridLoader.cpp
index acff2940241..aafe9b65d58 100644
--- a/src/server/game/Grids/ObjectGridLoader.cpp
+++ b/src/server/game/Grids/ObjectGridLoader.cpp
@@ -274,7 +274,7 @@ void ObjectGridStoper::Visit(CreatureMapType &m)
     {
         iter->GetSource()->RemoveAllDynObjects();
         iter->GetSource()->RemoveAllAreaTriggers();
-        if (iter->GetSource()->IsInCombat() || !iter->GetSource()->GetThreatManager().areThreatListsEmpty())
+        if (iter->GetSource()->IsInCombat())
         {
             iter->GetSource()->CombatStop();
             iter->GetSource()->GetThreatManager().ClearAllThreat();
diff --git a/src/server/game/Handlers/PetHandler.cpp b/src/server/game/Handlers/PetHandler.cpp
index 9a2863ae12c..c38a63201b1 100644
--- a/src/server/game/Handlers/PetHandler.cpp
+++ b/src/server/game/Handlers/PetHandler.cpp
@@ -134,7 +134,6 @@ void WorldSession::HandlePetStopAttack(WorldPackets::Pet::PetStopAttack& packet)
         return;
 
     pet->AttackStop();
-    pet->ClearInPetCombat();
 }
 
 void WorldSession::HandlePetActionHelper(Unit* pet, ObjectGuid guid1, uint32 spellid, uint16 flag, ObjectGuid guid2, Position const& pos)
@@ -168,7 +167,6 @@ void WorldSession::HandlePetActionHelper(Unit* pet, ObjectGuid guid1, uint32 spe
                 case COMMAND_FOLLOW:                        //spellid=1792  //FOLLOW
                     pet->AttackStop();
                     pet->InterruptNonMeleeSpells(false);
-                    pet->ClearInPetCombat();
                     pet->GetMotionMaster()->MoveFollow(_player, PET_FOLLOW_DIST, pet->GetFollowAngle());
                     charmInfo->SetCommandState(COMMAND_FOLLOW);
 
@@ -282,7 +280,6 @@ void WorldSession::HandlePetActionHelper(Unit* pet, ObjectGuid guid1, uint32 spe
             {
                 case REACT_PASSIVE:                         //passive
                     pet->AttackStop();
-                    pet->ClearInPetCombat();
                     /* fallthrough */
                 case REACT_DEFENSIVE:                       //recovery
                 case REACT_AGGRESSIVE:                      //activete
diff --git a/src/server/game/Maps/Map.cpp b/src/server/game/Maps/Map.cpp
index 91138fc043e..8d6d2e8f663 100644
--- a/src/server/game/Maps/Map.cpp
+++ b/src/server/game/Maps/Map.cpp
@@ -875,21 +875,10 @@ void Map::Update(uint32 t_diff)
         // Handle updates for creatures in combat with player and are more than 60 yards away
         if (player->IsInCombat())
         {
-            std::vector<Creature*> updateList;
-            HostileReference* ref = player->getHostileRefManager().getFirst();
-
-            while (ref)
-            {
-                if (Unit* unit = ref->GetSource()->GetOwner())
-                    if (unit->ToCreature() && unit->GetMapId() == player->GetMapId() && !unit->IsWithinDistInMap(player, GetVisibilityRange(), false))
-                        updateList.push_back(unit->ToCreature());
-
-                ref = ref->next();
-            }
-
-            // Process deferred update list for player
-            for (Creature* c : updateList)
-                VisitNearbyCellsOf(c, grid_object_update, world_object_update);
+            for (auto const& pair : player->GetCombatManager().GetPvECombatRefs())
+                if (Creature* unit = pair.second->GetOther(player)->ToCreature())
+                    if (unit->GetMapId() == player->GetMapId() && !unit->IsWithinDistInMap(player, GetVisibilityRange(), false))
+                        VisitNearbyCellsOf(unit, grid_object_update, world_object_update);
         }
     }
 
@@ -1040,7 +1029,7 @@ void Map::RemovePlayerFromMap(Player* player, bool remove)
     player->UpdateZone(MAP_INVALID_ZONE, 0);
     sScriptMgr->OnPlayerLeaveMap(this, player);
 
-    player->getHostileRefManager().deleteReferences(); // multithreading crashfix
+    player->CombatStop();
 
     bool const inWorld = player->IsInWorld();
     player->RemoveFromWorld();
diff --git a/src/server/game/Movement/MovementGenerators/FlightPathMovementGenerator.cpp b/src/server/game/Movement/MovementGenerators/FlightPathMovementGenerator.cpp
index 483ebc4841f..1e07dbd1a31 100644
--- a/src/server/game/Movement/MovementGenerators/FlightPathMovementGenerator.cpp
+++ b/src/server/game/Movement/MovementGenerators/FlightPathMovementGenerator.cpp
@@ -117,7 +117,6 @@ void FlightPathMovementGenerator::DoFinalize(Player* player)
 
     if (player->m_taxi.empty())
     {
-        player->getHostileRefManager().setOnlineOfflineState(true);
         // update z position to ground and orientation for landing point
         // this prevent cheating with landing  point at lags
         // when client side flight end early in comparison server side
@@ -131,8 +130,8 @@ void FlightPathMovementGenerator::DoFinalize(Player* player)
 
 void FlightPathMovementGenerator::DoReset(Player* player)
 {
-    player->getHostileRefManager().setOnlineOfflineState(false);
     player->AddUnitState(UNIT_STATE_IN_FLIGHT);
+    player->CombatStopWithPets();
     player->AddUnitFlag(UnitFlags(UNIT_FLAG_REMOVE_CLIENT_CONTROL | UNIT_FLAG_TAXI_FLIGHT));
 
     Movement::MoveSplineInit init(player);
diff --git a/src/server/game/Server/WorldSession.cpp b/src/server/game/Server/WorldSession.cpp
index 1cb18499c12..9631b1c007e 100644
--- a/src/server/game/Server/WorldSession.cpp
+++ b/src/server/game/Server/WorldSession.cpp
@@ -508,7 +508,7 @@ void WorldSession::LogoutPlayer(bool save)
         ///- If the player just died before logging out, make him appear as a ghost
         if (_player->GetDeathTimer())
         {
-            _player->getHostileRefManager().deleteReferences();
+            _player->CombatStop();
             _player->BuildPlayerRepop();
             _player->RepopAtGraveyard();
         }
diff --git a/src/server/game/Spells/Auras/SpellAuraEffects.cpp b/src/server/game/Spells/Auras/SpellAuraEffects.cpp
index c3a135b69e5..5653a456002 100644
--- a/src/server/game/Spells/Auras/SpellAuraEffects.cpp
+++ b/src/server/game/Spells/Auras/SpellAuraEffects.cpp
@@ -288,7 +288,7 @@ NonDefaultConstructible<pAuraEffectHandler> AuraEffectHandler[TOTAL_AURAS]=
     &AuraEffect::HandleNULL,                                      //218 SPELL_AURA_ADD_PCT_MODIFIER_BY_SPELL_LABEL
     &AuraEffect::HandleNULL,                                      //219 SPELL_AURA_ADD_FLAT_MODIFIER_BY_SPELL_LABEL
     &AuraEffect::HandleNULL,                                      //220 SPELL_AURA_MOD_ABILITY_SCHOOL_MASK
-    &AuraEffect::HandleNULL,                                      //221 SPELL_AURA_MOD_DETAUNT
+    &AuraEffect::HandleModDetaunt,                                //221 SPELL_AURA_MOD_DETAUNT
     &AuraEffect::HandleNoImmediateEffect,                         //222 SPELL_AURA_REMOVE_TRANSMOG_COST implemented in WorldSession::HandleTransmogrifyItems
     &AuraEffect::HandleNoImmediateEffect,                         //223 SPELL_AURA_REMOVE_BARBER_SHOP_COST implemented in Player::GetBarberShopCost
     &AuraEffect::HandleNULL,                                      //224 SPELL_AURA_LEARN_TALENT
@@ -1975,6 +1975,8 @@ void AuraEffect::HandleAuraTransform(AuraApplication const* aurApp, uint8 mode,
             }
         }
     }
+
+    target->GetThreatManager().UpdateOnlineStates(true, false);
 }
 
 void AuraEffect::HandleAuraModScale(AuraApplication const* aurApp, uint8 mode, bool apply) const
@@ -2045,13 +2047,20 @@ void AuraEffect::HandleFeignDeath(AuraApplication const* aurApp, uint8 mode, boo
                 }
             }
         }
-        target->CombatStop();
+
+        if (target->GetMap()->IsDungeon()) // feign death does not remove combat in dungeons
+        {
+            target->AttackStop();
+            if (Player* targetPlayer = target->ToPlayer())
+                targetPlayer->SendAttackSwingCancelAttack();
+        }
+        else
+            target->CombatStop(false, false);
 
         // prevent interrupt message
         if (GetCasterGUID() == target->GetGUID() && target->GetCurrentSpell(CURRENT_GENERIC_SPELL))
             target->FinishSpell(CURRENT_GENERIC_SPELL, false);
         target->InterruptNonMeleeSpells(true);
-        target->getHostileRefManager().deleteReferences();
 
         // stop handling the effect if it was removed by linked event
         if (aurApp->GetRemoveMode())
@@ -2075,6 +2084,7 @@ void AuraEffect::HandleFeignDeath(AuraApplication const* aurApp, uint8 mode, boo
         if (Creature* creature = target->ToCreature())
             creature->InitializeReactState();
     }
+    target->GetThreatManager().UpdateOnlineStates(true, false);
 }
 
 void AuraEffect::HandleModUnattackable(AuraApplication const* aurApp, uint8 mode, bool apply) const
@@ -2095,7 +2105,16 @@ void AuraEffect::HandleModUnattackable(AuraApplication const* aurApp, uint8 mode
 
     // call functions which may have additional effects after chainging state of unit
     if (apply && (mode & AURA_EFFECT_HANDLE_REAL))
-        target->CombatStop();
+    {
+        if (target->GetMap()->IsDungeon())
+        {
+            target->AttackStop();
+            if (Player* targetPlayer = target->ToPlayer())
+                targetPlayer->SendAttackSwingCancelAttack();
+        }
+        else
+            target->CombatStop();
+    }
 }
 
 void AuraEffect::HandleAuraModDisarm(AuraApplication const* aurApp, uint8 mode, bool apply) const
@@ -2655,28 +2674,15 @@ void AuraEffect::HandleIgnoreMovementForces(AuraApplication const* aurApp, uint8
 /***        THREAT        ***/
 /****************************/
 
-void AuraEffect::HandleModThreat(AuraApplication const* aurApp, uint8 mode, bool apply) const
+void AuraEffect::HandleModThreat(AuraApplication const* aurApp, uint8 mode, bool /*apply*/) const
 {
     if (!(mode & AURA_EFFECT_HANDLE_CHANGE_AMOUNT_MASK))
         return;
 
-    Unit* target = aurApp->GetTarget();
-    for (uint8 i = 0; i < MAX_SPELL_SCHOOL; ++i)
-    {
-        if (GetMiscValue() & (1 << i))
-        {
-            if (apply)
-                AddPct(target->m_threatModifier[i], GetAmount());
-            else
-            {
-                float amount = target->GetTotalAuraMultiplierByMiscMask(SPELL_AURA_MOD_THREAT, 1 << i);
-                target->m_threatModifier[i] = amount;
-            }
-        }
-    }
+    aurApp->GetTarget()->GetThreatManager().UpdateMySpellSchoolModifiers();
 }
 
-void AuraEffect::HandleAuraModTotalThreat(AuraApplication const* aurApp, uint8 mode, bool apply) const
+void AuraEffect::HandleAuraModTotalThreat(AuraApplication const* aurApp, uint8 mode, bool /*apply*/) const
 {
     if (!(mode & AURA_EFFECT_HANDLE_CHANGE_AMOUNT_MASK))
         return;
@@ -2688,10 +2694,10 @@ void AuraEffect::HandleAuraModTotalThreat(AuraApplication const* aurApp, uint8 m
 
     Unit* caster = GetCaster();
     if (caster && caster->IsAlive())
-        target->getHostileRefManager().addTempThreat((float)GetAmount(), apply);
+        caster->GetThreatManager().UpdateMyTempModifiers();
 }
 
-void AuraEffect::HandleModTaunt(AuraApplication const* aurApp, uint8 mode, bool apply) const
+void AuraEffect::HandleModTaunt(AuraApplication const* aurApp, uint8 mode, bool /*apply*/) const
 {
     if (!(mode & AURA_EFFECT_HANDLE_REAL))
         return;
@@ -2701,17 +2707,21 @@ void AuraEffect::HandleModTaunt(AuraApplication const* aurApp, uint8 mode, bool
     if (!target->IsAlive() || !target->CanHaveThreatList())
         return;
 
+    target->GetThreatManager().TauntUpdate();
+}
+
+void AuraEffect::HandleModDetaunt(AuraApplication const* aurApp, uint8 mode, bool /*apply*/) const
+{
+    if (!(mode & AURA_EFFECT_HANDLE_REAL))
+        return;
+
     Unit* caster = GetCaster();
-    if (!caster || !caster->IsAlive())
+    Unit* target = aurApp->GetTarget();
+
+    if (!caster || !caster->IsAlive() || !target->IsAlive() || !caster->CanHaveThreatList())
         return;
 
-    if (apply)
-        target->TauntApply(caster);
-    else
-    {
-        // When taunt aura fades out, mob will switch to previous target if current has less than 1.1 * secondthreat
-        target->TauntFadeOut(caster);
-    }
+    caster->GetThreatManager().TauntUpdate();
 }
 
 /*****************************/
@@ -2726,6 +2736,7 @@ void AuraEffect::HandleModConfuse(AuraApplication const* aurApp, uint8 mode, boo
     Unit* target = aurApp->GetTarget();
 
     target->SetControlled(apply, UNIT_STATE_CONFUSED);
+    target->GetThreatManager().UpdateOnlineStates(true, false);
 }
 
 void AuraEffect::HandleModFear(AuraApplication const* aurApp, uint8 mode, bool apply) const
@@ -2736,6 +2747,7 @@ void AuraEffect::HandleModFear(AuraApplication const* aurApp, uint8 mode, bool a
     Unit* target = aurApp->GetTarget();
 
     target->SetControlled(apply, UNIT_STATE_FLEEING);
+    target->GetThreatManager().UpdateOnlineStates(true, false);
 }
 
 void AuraEffect::HandleAuraModStun(AuraApplication const* aurApp, uint8 mode, bool apply) const
@@ -2746,6 +2758,7 @@ void AuraEffect::HandleAuraModStun(AuraApplication const* aurApp, uint8 mode, bo
     Unit* target = aurApp->GetTarget();
 
     target->SetControlled(apply, UNIT_STATE_STUNNED);
+    target->GetThreatManager().UpdateOnlineStates(true, false);
 }
 
 void AuraEffect::HandleAuraModRoot(AuraApplication const* aurApp, uint8 mode, bool apply) const
@@ -2756,6 +2769,7 @@ void AuraEffect::HandleAuraModRoot(AuraApplication const* aurApp, uint8 mode, bo
     Unit* target = aurApp->GetTarget();
 
     target->SetControlled(apply, UNIT_STATE_ROOT);
+    target->GetThreatManager().UpdateOnlineStates(true, false);
 }
 
 void AuraEffect::HandlePreventFleeing(AuraApplication const* aurApp, uint8 mode, bool apply) const
@@ -3136,6 +3150,8 @@ void AuraEffect::HandleAuraModSchoolImmunity(AuraApplication const* aurApp, uint
             && GetSpellInfo()->HasAttribute(SPELL_ATTR2_DAMAGE_REDUCED_SHIELD))
             target->RemoveAurasWithInterruptFlags(SpellAuraInterruptFlags::StealthOrInvis);
     }
+
+    target->GetThreatManager().UpdateOnlineStates(true, false);
 }
 
 void AuraEffect::HandleAuraModDmgImmunity(AuraApplication const* aurApp, uint8 mode, bool apply) const
@@ -3145,6 +3161,8 @@ void AuraEffect::HandleAuraModDmgImmunity(AuraApplication const* aurApp, uint8 m
 
     Unit* target = aurApp->GetTarget();
     m_spellInfo->ApplyAllSpellImmunitiesTo(target, GetSpellEffectInfo(), apply);
+
+    target->GetThreatManager().UpdateOnlineStates(true, false);
 }
 
 void AuraEffect::HandleAuraModDispelImmunity(AuraApplication const* aurApp, uint8 mode, bool apply) const
@@ -4771,7 +4789,7 @@ void AuraEffect::HandleForceReaction(AuraApplication const* aurApp, uint8 mode,
     player->GetReputationMgr().ApplyForceReaction(factionId, factionRank, apply);
     player->GetReputationMgr().SendForceReactions();
 
-    // stop fighting if at apply forced rank friendly or at remove real rank friendly
+    // stop fighting at apply (if forced rank friendly) or at remove (if real rank friendly)
     if ((apply && factionRank >= REP_FRIENDLY) || (!apply && player->GetReputationRank(factionId) >= REP_FRIENDLY))
         player->StopAttackFaction(factionId);
 }
diff --git a/src/server/game/Spells/Auras/SpellAuraEffects.h b/src/server/game/Spells/Auras/SpellAuraEffects.h
index 8f5f1eb2efb..ff6cba63688 100644
--- a/src/server/game/Spells/Auras/SpellAuraEffects.h
+++ b/src/server/game/Spells/Auras/SpellAuraEffects.h
@@ -193,6 +193,7 @@ class TC_GAME_API AuraEffect
         void HandleModThreat(AuraApplication const* aurApp, uint8 mode, bool apply) const;
         void HandleAuraModTotalThreat(AuraApplication const* aurApp, uint8 mode, bool apply) const;
         void HandleModTaunt(AuraApplication const* aurApp, uint8 mode, bool apply) const;
+        void HandleModDetaunt(AuraApplication const* aurApp, uint8 mode, bool apply) const;
         //  control
         void HandleModConfuse(AuraApplication const* aurApp, uint8 mode, bool apply) const;
         void HandleModFear(AuraApplication const* aurApp, uint8 mode, bool apply) const;
diff --git a/src/server/game/Spells/Spell.cpp b/src/server/game/Spells/Spell.cpp
index 54cf9337114..8b0733a4b92 100644
--- a/src/server/game/Spells/Spell.cpp
+++ b/src/server/game/Spells/Spell.cpp
@@ -2560,7 +2560,7 @@ void Spell::DoAllEffectOnTarget(TargetInfo* target)
     // spellHitTarget can be null if spell is missed in DoSpellHitOnUnit
     if (missInfo != SPELL_MISS_EVADE && spellHitTarget && !m_caster->IsFriendlyTo(unit) && (!IsPositive() || m_spellInfo->HasEffect(SPELL_EFFECT_DISPEL)))
     {
-        m_caster->CombatStart(unit, m_spellInfo->HasInitialAggro());
+        m_caster->AttackedTarget(unit, m_spellInfo->HasInitialAggro());
 
         if (!unit->IsStandState())
             unit->SetStandState(UNIT_STAND_STATE_STAND);
@@ -2655,7 +2655,8 @@ SpellMissInfo Spell::DoSpellHitOnUnit(Unit* unit, uint32 effectMask)
             }
             if (unit->IsInCombat() && m_spellInfo->HasInitialAggro())
             {
-                m_caster->SetInCombatState(unit->GetCombatTimer() > 0, unit);
+                if (m_caster->HasUnitFlag(UNIT_FLAG_PVP_ATTACKABLE))               // only do explicit combat forwarding for PvP enabled units
+                    m_caster->GetCombatManager().InheritCombatStatesFrom(unit);    // for creature v creature combat, the threat forward does it for us
                 unit->GetThreatManager().ForwardThreatForAssistingMe(m_caster, 0.0f, nullptr, true);
             }
         }
@@ -7459,6 +7460,10 @@ void Spell::DoAllEffectOnLaunchTarget(TargetInfo& targetInfo, float* multiplier)
     if (!unit)
         return;
 
+    // This will only cause combat - the target will engage once the projectile hits (in DoAllEffectOnTarget)
+    if (targetInfo.missCondition != SPELL_MISS_EVADE && !m_caster->IsFriendlyTo(unit) && (!m_spellInfo->IsPositive() || m_spellInfo->HasEffect(SPELL_EFFECT_DISPEL)) && (m_spellInfo->HasInitialAggro() || unit->IsEngaged()))
+        m_caster->SetInCombatWith(unit);
+
     for (SpellEffectInfo const* effect : m_spellInfo->GetEffects())
     {
         if (effect && (targetInfo.effectMask & (1<<effect->EffectIndex)))
@@ -8043,7 +8048,7 @@ bool WorldObjectSpellTargetCheck::operator()(WorldObject* target)
                     return false;
                 break;
             case TARGET_CHECK_THREAT:
-                if (_referer->GetThreatManager().getThreat(unitTarget, true) <= 0.0f)
+                if (_referer->GetThreatManager().GetThreat(unitTarget, true) <= 0.0f)
                     return false;
                 break;
             case TARGET_CHECK_TAP:
diff --git a/src/server/game/Spells/SpellEffects.cpp b/src/server/game/Spells/SpellEffects.cpp
index d44e84529c4..a0a1b6fb26b 100644
--- a/src/server/game/Spells/SpellEffects.cpp
+++ b/src/server/game/Spells/SpellEffects.cpp
@@ -1090,7 +1090,7 @@ void Spell::EffectPowerDrain(SpellEffIndex effIndex)
 
         int32 gain = int32(newDamage* gainMultiplier);
 
-        m_caster->EnergizeBySpell(m_caster, m_spellInfo->Id, gain, powerType);
+        m_caster->EnergizeBySpell(m_caster, m_spellInfo, gain, powerType);
     }
     ExecuteLogEffectTakeTargetPower(effIndex, unitTarget, powerType, newDamage, gainMultiplier);
 }
@@ -1522,7 +1522,7 @@ void Spell::EffectEnergize(SpellEffIndex /*effIndex*/)
             break;
     }
 
-    m_caster->EnergizeBySpell(unitTarget, m_spellInfo->Id, damage, power);
+    m_caster->EnergizeBySpell(unitTarget, m_spellInfo, damage, power);
 }
 
 void Spell::EffectEnergizePct(SpellEffIndex /*effIndex*/)
@@ -1544,7 +1544,7 @@ void Spell::EffectEnergizePct(SpellEffIndex /*effIndex*/)
         return;
 
     uint32 gain = CalculatePct(maxPower, damage);
-    m_caster->EnergizeBySpell(unitTarget, m_spellInfo->Id, gain, power);
+    m_caster->EnergizeBySpell(unitTarget, m_spellInfo, gain, power);
 }
 
 void Spell::SendLoot(ObjectGuid guid, LootType loottype)
@@ -2700,27 +2700,22 @@ void Spell::EffectTaunt(SpellEffIndex /*effIndex*/)
 
     // this effect use before aura Taunt apply for prevent taunt already attacking target
     // for spell as marked "non effective at already attacking target"
-    if (!unitTarget || !unitTarget->CanHaveThreatList() || unitTarget->GetVictim() == m_caster)
+    if (!unitTarget || !unitTarget->CanHaveThreatList())
     {
         SendCastResult(SPELL_FAILED_DONT_REPORT);
         return;
     }
 
-    if (!unitTarget->GetThreatManager().getOnlineContainer().empty())
+    ThreatManager& mgr = unitTarget->GetThreatManager();
+    if (mgr.GetCurrentVictim() == m_caster)
     {
-        // Also use this effect to set the taunter's threat to the taunted creature's highest value
-        float myThreat = unitTarget->GetThreatManager().getThreat(m_caster);
-        float topThreat = unitTarget->GetThreatManager().getOnlineContainer().getMostHated()->getThreat();
-        if (topThreat > myThreat)
-            unitTarget->GetThreatManager().doAddThreat(m_caster, topThreat - myThreat);
-
-        //Set aggro victim to caster
-        if (HostileReference* forcedVictim = unitTarget->GetThreatManager().getOnlineContainer().getReferenceByTarget(m_caster))
-            unitTarget->GetThreatManager().setCurrentVictim(forcedVictim);
+        SendCastResult(SPELL_FAILED_DONT_REPORT);
+        return;
     }
 
-    if (unitTarget->ToCreature()->IsAIEnabled && !unitTarget->ToCreature()->HasReactState(REACT_PASSIVE))
-        unitTarget->ToCreature()->AI()->AttackStart(m_caster);
+    if (!mgr.IsThreatListEmpty())
+        // Set threat equal to highest threat currently on target
+        mgr.MatchUnitThreatToHighestThreat(m_caster);
 }
 
 void Spell::EffectWeaponDmg(SpellEffIndex effIndex)
@@ -2920,13 +2915,13 @@ void Spell::EffectThreat(SpellEffIndex /*effIndex*/)
     if (effectHandleMode != SPELL_EFFECT_HANDLE_HIT_TARGET)
         return;
 
-    if (!unitTarget || !unitTarget->IsAlive() || !m_caster->IsAlive())
+    if (!unitTarget || !m_caster->IsAlive())
         return;
 
     if (!unitTarget->CanHaveThreatList())
         return;
 
-    unitTarget->GetThreatManager().AddThreat(m_caster, float(damage));
+    unitTarget->GetThreatManager().AddThreat(m_caster, float(damage), m_spellInfo, true);
 }
 
 void Spell::EffectHealMaxHealth(SpellEffIndex /*effIndex*/)
@@ -3456,20 +3451,19 @@ void Spell::EffectSanctuary(SpellEffIndex /*effIndex*/)
     if (!unitTarget)
         return;
 
-    if (unitTarget->GetTypeId() == TYPEID_PLAYER)
-        unitTarget->ToPlayer()->SendAttackSwingCancelAttack();     // melee and ranged forced attack cancel
-
-    unitTarget->getHostileRefManager().UpdateVisibility();
-
-    Unit::AttackerSet const& attackers = unitTarget->getAttackers();
-    for (Unit::AttackerSet::const_iterator itr = attackers.begin(); itr != attackers.end();)
+    if (unitTarget->GetTypeId() == TYPEID_PLAYER && !unitTarget->GetMap()->IsDungeon())
     {
-        if (!(*itr)->CanSeeOrDetect(unitTarget))
-            (*(itr++))->AttackStop();
-        else
-            ++itr;
+        // stop all pve combat for players outside dungeons, suppress pvp combat
+        unitTarget->CombatStop(false, false);
+    }
+    else
+    {
+        // in dungeons (or for nonplayers), reset this unit on all enemies' threat lists
+        for (auto const& pair : unitTarget->GetThreatManager().GetThreatenedByMeList())
+            pair.second->SetThreat(0.0f);
     }
 
+    // makes spells cast before this time fizzle
     unitTarget->m_lastSanctuaryTime = GameTime::GetGameTimeMS();
 }
 
@@ -5015,7 +5009,7 @@ void Spell::EffectRedirectThreat(SpellEffIndex /*effIndex*/)
         return;
 
     if (unitTarget)
-        m_caster->SetRedirectThreat(unitTarget->GetGUID(), uint32(damage));
+        m_caster->GetThreatManager().RegisterRedirectThreat(m_spellInfo->Id, unitTarget->GetGUID(), uint32(damage));
 }
 
 void Spell::EffectGameObjectDamage(SpellEffIndex /*effIndex*/)
diff --git a/src/server/game/Spells/SpellInfo.cpp b/src/server/game/Spells/SpellInfo.cpp
index de90ff466e5..88a598204a1 100644
--- a/src/server/game/Spells/SpellInfo.cpp
+++ b/src/server/game/Spells/SpellInfo.cpp
@@ -2106,8 +2106,8 @@ SpellCastResult SpellInfo::CheckTarget(Unit const* caster, WorldObject const* ta
     // creature/player specific target checks
     if (unitTarget)
     {
-        // spells cannot be cast if player is in fake combat also
-        if (HasAttribute(SPELL_ATTR1_CANT_TARGET_IN_COMBAT) && (unitTarget->IsInCombat() || unitTarget->IsPetInCombat()))
+        // spells cannot be cast if target has a pet in combat either
+        if (HasAttribute(SPELL_ATTR1_CANT_TARGET_IN_COMBAT) && (unitTarget->IsInCombat() || unitTarget->HasUnitFlag(UNIT_FLAG_PET_IN_COMBAT)))
             return SPELL_FAILED_TARGET_AFFECTING_COMBAT;
 
         // only spells with SPELL_ATTR3_ONLY_TARGET_GHOSTS can target ghosts
diff --git a/src/server/scripts/Commands/cs_debug.cpp b/src/server/scripts/Commands/cs_debug.cpp
index 15372bc0882..b46b8cfd978 100644
--- a/src/server/scripts/Commands/cs_debug.cpp
+++ b/src/server/scripts/Commands/cs_debug.cpp
@@ -846,23 +846,73 @@ public:
 
     static bool HandleDebugThreatListCommand(ChatHandler* handler, char const* /*args*/)
     {
-        Creature* target = handler->getSelectedCreature();
-        if (!target || target->IsTotem() || target->IsPet())
-            return false;
+        Unit* target = handler->getSelectedUnit();
+        if (!target)
+            target = handler->GetSession()->GetPlayer();
+        
+        ThreatManager& mgr = target->GetThreatManager();
+        if (!target->IsAlive())
+        {
+            handler->PSendSysMessage("%s (%s) is not alive.", target->GetName().c_str(), target->GetGUID().ToString().c_str());
+            return true;
+        }
+        if (!target->CanHaveThreatList())
+            handler->PSendSysMessage("%s (%s) cannot have a threat list.", target->GetName().c_str(), target->GetGUID().ToString().c_str());
 
-        ThreatContainer::StorageType const& threatList = target->GetThreatManager().getThreatList();
-        ThreatContainer::StorageType::const_iterator itr;
         uint32 count = 0;
-        handler->PSendSysMessage("Threat list of %s (%s)", target->GetName().c_str(), target->GetGUID().ToString().c_str());
-        for (itr = threatList.begin(); itr != threatList.end(); ++itr)
+        auto const& threatenedByMe = target->GetThreatManager().GetThreatenedByMeList();
+        if (threatenedByMe.empty())
+            handler->PSendSysMessage("%s (%s) does not threaten any units.", target->GetName().c_str(), target->GetGUID().ToString().c_str());
+        else
         {
-            Unit* unit = (*itr)->getTarget();
-            if (!unit)
-                continue;
-            ++count;
-            handler->PSendSysMessage("   %u.   %s   (%s)  - threat %f", count, unit->GetName().c_str(), unit->GetGUID().ToString().c_str(), (*itr)->getThreat());
+            handler->PSendSysMessage("List of units threatened by %s (%s)", target->GetName().c_str(), target->GetGUID().ToString().c_str());
+            for (auto const& pair : threatenedByMe)
+            {
+                Unit* unit = pair.second->GetOwner();
+                handler->PSendSysMessage("   %u.   %s   (%s, SpawnID %u)  - threat %f", ++count, unit->GetName().c_str(), unit->GetGUID().ToString().c_str(), unit->GetTypeId() == TYPEID_UNIT ? unit->ToCreature()->GetSpawnId() : 0, pair.second->GetThreat());
+            }
+            handler->SendSysMessage("End of threatened-by-me list.");
         }
-        handler->SendSysMessage("End of threat list.");
+
+        if (!mgr.CanHaveThreatList())
+            return true;
+        if (mgr.IsEngaged())
+        {
+            count = 0;
+            handler->PSendSysMessage("Threat list of %s (%s, SpawnID %u)", target->GetName().c_str(), target->GetGUID().ToString().c_str(), target->GetTypeId() == TYPEID_UNIT ? target->ToCreature()->GetSpawnId() : 0);
+            for (ThreatReference const* ref : mgr.GetSortedThreatList())
+            {
+                Unit* unit = ref->GetVictim();
+                char const* onlineStr;
+                switch (ref->GetOnlineState())
+                {
+                    case ThreatReference::ONLINE_STATE_SUPPRESSED:
+                        onlineStr = " [SUPPRESSED]";
+                        break;
+                    case ThreatReference::ONLINE_STATE_OFFLINE:
+                        onlineStr = " [OFFLINE]";
+                        break;
+                    default:
+                        onlineStr = "";
+                }
+                char const* tauntStr;
+                switch (ref->GetTauntState())
+                {
+                    case ThreatReference::TAUNT_STATE_TAUNT:
+                        tauntStr = " [TAUNT]";
+                        break;
+                    case ThreatReference::TAUNT_STATE_DETAUNT:
+                        tauntStr = " [DETAUNT]";
+                        break;
+                    default:
+                        tauntStr = "";
+                }
+                handler->PSendSysMessage("   %u.   %s   (%s)  - threat %f%s%s", ++count, unit->GetName().c_str(), unit->GetGUID().ToString().c_str(), ref->GetThreat(), tauntStr, onlineStr);
+            }
+            handler->SendSysMessage("End of threat list.");
+        }
+        else
+            handler->PSendSysMessage("%s (%s, SpawnID %u) is not currently engaged.", target->GetName().c_str(), target->GetGUID().ToString().c_str(), target->GetTypeId() == TYPEID_UNIT ? target->ToCreature()->GetSpawnId() : 0);
         return true;
     }
 
@@ -871,19 +921,18 @@ public:
         Unit* target = handler->getSelectedUnit();
         if (!target)
             target = handler->GetSession()->GetPlayer();
-        HostileReference* ref = target->getHostileRefManager().getFirst();
-        uint32 count = 0;
-        handler->PSendSysMessage("Hostil reference list of %s (%s)", target->GetName().c_str(), target->GetGUID().ToString().c_str());
-        while (ref)
+
+        handler->PSendSysMessage("Combat refs: (Combat state: %d | Manager state: %d)", target->IsInCombat(), target->GetCombatManager().HasCombat());
+        for (auto const& ref : target->GetCombatManager().GetPvPCombatRefs())
         {
-            if (Unit* unit = ref->GetSource()->GetOwner())
-            {
-                ++count;
-                handler->PSendSysMessage("   %u.   %s   (%s, SpawnId: %s)  - threat %f", count, unit->GetName().c_str(), unit->GetGUID().ToString().c_str(), unit->GetTypeId() == TYPEID_UNIT ? std::to_string(unit->ToCreature()->GetSpawnId()).c_str() : "0", ref->getThreat());
-            }
-            ref = ref->next();
+            Unit* unit = ref.second->GetOther(target);
+            handler->PSendSysMessage("[PvP] %s (SpawnID %u)", unit->GetName().c_str(), unit->GetTypeId() == TYPEID_UNIT ? unit->ToCreature()->GetSpawnId() : 0);
+        }
+        for (auto const& ref : target->GetCombatManager().GetPvECombatRefs())
+        {
+            Unit* unit = ref.second->GetOther(target);
+            handler->PSendSysMessage("[PvE] %s (SpawnID %u)", unit->GetName().c_str(), unit->GetTypeId() == TYPEID_UNIT ? unit->ToCreature()->GetSpawnId() : 0);
         }
-        handler->SendSysMessage("End of hostil reference list.");
         return true;
     }
 
diff --git a/src/server/scripts/Commands/cs_misc.cpp b/src/server/scripts/Commands/cs_misc.cpp
index 0b3547670bc..c8fe798fcaf 100644
--- a/src/server/scripts/Commands/cs_misc.cpp
+++ b/src/server/scripts/Commands/cs_misc.cpp
@@ -2491,7 +2491,6 @@ public:
             return false;
 
         target->CombatStop();
-        target->getHostileRefManager().deleteReferences();
         return true;
     }
 
diff --git a/src/server/scripts/EasternKingdoms/BaradinHold/boss_occuthar.cpp b/src/server/scripts/EasternKingdoms/BaradinHold/boss_occuthar.cpp
index 438230d622a..f2c8ef442ea 100644
--- a/src/server/scripts/EasternKingdoms/BaradinHold/boss_occuthar.cpp
+++ b/src/server/scripts/EasternKingdoms/BaradinHold/boss_occuthar.cpp
@@ -212,7 +212,7 @@ class FocusedFireTargetSelector : public std::unary_function<Unit *, bool>
 
         bool operator() (WorldObject* target)
         {
-            if (target == _victim && _me->GetThreatManager().getThreatList().size() > 1)
+            if (target == _victim && _me->GetThreatManager().GetThreatListSize() > 1)
                 return true;
 
             if (target->GetTypeId() != TYPEID_PLAYER)
diff --git a/src/server/scripts/EasternKingdoms/MagistersTerrace/boss_felblood_kaelthas.cpp b/src/server/scripts/EasternKingdoms/MagistersTerrace/boss_felblood_kaelthas.cpp
index 0338a3ad73f..6e0d047514e 100644
--- a/src/server/scripts/EasternKingdoms/MagistersTerrace/boss_felblood_kaelthas.cpp
+++ b/src/server/scripts/EasternKingdoms/MagistersTerrace/boss_felblood_kaelthas.cpp
@@ -198,30 +198,21 @@ public:
             if (!summonedUnit)
                 return;
 
-            ThreatContainer::StorageType const& threatlist = me->GetThreatManager().getThreatList();
-            ThreatContainer::StorageType::const_iterator i = threatlist.begin();
-            for (i = threatlist.begin(); i != threatlist.end(); ++i)
+            for (auto* ref : me->GetThreatManager().GetUnsortedThreatList())
             {
-                Unit* unit = ObjectAccessor::GetUnit(*me, (*i)->getUnitGuid());
+                Unit* unit = ref->GetVictim();
                 if (unit && unit->IsAlive())
-                {
-                    float threat = me->GetThreatManager().getThreat(unit);
-                    AddThreat(unit, threat, summonedUnit);
-                }
+                    AddThreat(unit, ref->GetThreat(), summonedUnit);
             }
         }
 
         void TeleportPlayersToSelf()
         {
-            float x = KaelLocations[0][0];
-            float y = KaelLocations[0][1];
-            me->UpdatePosition(x, y, LOCATION_Z, 0.0f);
-            ThreatContainer::StorageType threatlist = me->GetThreatManager().getThreatList();
-            ThreatContainer::StorageType::const_iterator i = threatlist.begin();
-            for (i = threatlist.begin(); i != threatlist.end(); ++i)
+            me->UpdatePosition(KaelLocations[0][0], KaelLocations[0][1], LOCATION_Z, 0.0f);
+            for (auto const& pair : me->GetCombatManager().GetPvECombatRefs())
             {
-                Unit* unit = ObjectAccessor::GetUnit(*me, (*i)->getUnitGuid());
-                if (unit && (unit->GetTypeId() == TYPEID_PLAYER))
+                Unit* unit = pair.second->GetOther(me);
+                if (unit->GetTypeId() == TYPEID_PLAYER)
                     unit->CastSpell(unit, SPELL_TELEPORT_CENTER, true);
             }
             DoCast(me, SPELL_TELEPORT_CENTER, true);
@@ -229,14 +220,11 @@ public:
 
         void CastGravityLapseKnockUp()
         {
-            ThreatContainer::StorageType threatlist = me->GetThreatManager().getThreatList();
-            ThreatContainer::StorageType::const_iterator i = threatlist.begin();
-            for (i = threatlist.begin(); i != threatlist.end(); ++i)
+            for (auto const& pair : me->GetCombatManager().GetPvECombatRefs())
             {
-                Unit* unit = ObjectAccessor::GetUnit(*me, (*i)->getUnitGuid());
-                if (unit && (unit->GetTypeId() == TYPEID_PLAYER))
+                Unit* unit = pair.second->GetOther(me);
+                if (unit->GetTypeId() == TYPEID_PLAYER)
                 {
-                    // Knockback into the air
                     CastSpellExtraArgs args;
                     args.TriggerFlags = TRIGGERED_FULL_MASK;
                     args.OriginalCaster = me->GetGUID();
@@ -247,12 +235,10 @@ public:
 
         void CastGravityLapseFly()                              // Use Fly Packet hack for now as players can't cast "fly" spells unless in map 530. Has to be done a while after they get knocked into the air...
         {
-            ThreatContainer::StorageType threatlist = me->GetThreatManager().getThreatList();
-            ThreatContainer::StorageType::const_iterator i = threatlist.begin();
-            for (i = threatlist.begin(); i != threatlist.end(); ++i)
+            for (auto const& pair : me->GetCombatManager().GetPvECombatRefs())
             {
-                Unit* unit = ObjectAccessor::GetUnit(*me, (*i)->getUnitGuid());
-                if (unit && (unit->GetTypeId() == TYPEID_PLAYER))
+                Unit* unit = pair.second->GetOther(me);
+                if (unit->GetTypeId() == TYPEID_PLAYER)
                 {
                     // Also needs an exception in spell system.
                     CastSpellExtraArgs args;
@@ -266,12 +252,10 @@ public:
 
         void RemoveGravityLapse()
         {
-            ThreatContainer::StorageType threatlist = me->GetThreatManager().getThreatList();
-            ThreatContainer::StorageType::const_iterator i = threatlist.begin();
-            for (i = threatlist.begin(); i != threatlist.end(); ++i)
+            for (auto const& pair : me->GetCombatManager().GetPvECombatRefs())
             {
-                Unit* unit = ObjectAccessor::GetUnit(*me, (*i)->getUnitGuid());
-                if (unit && (unit->GetTypeId() == TYPEID_PLAYER))
+                Unit* unit = pair.second->GetOther(me);
+                if (unit->GetTypeId() == TYPEID_PLAYER)
                 {
                     unit->RemoveAurasDueToSpell(SPELL_GRAVITY_LAPSE_FLY);
                     unit->RemoveAurasDueToSpell(SPELL_GRAVITY_LAPSE_DOT);
@@ -684,8 +668,8 @@ public:
             {
                 if (Unit* target = SelectTarget(SELECT_TARGET_RANDOM, 0, 100, true))
                 {
-                    AddThreat(target, 1.0f);
-                    me->TauntApply(target);
+                    ResetThreatList();
+                    AddThreat(target, 1000000.0f);
                     AttackStart(target);
                 }
 
diff --git a/src/server/scripts/EasternKingdoms/MagistersTerrace/boss_priestess_delrissa.cpp b/src/server/scripts/EasternKingdoms/MagistersTerrace/boss_priestess_delrissa.cpp
index e50740d8dac..21417362610 100644
--- a/src/server/scripts/EasternKingdoms/MagistersTerrace/boss_priestess_delrissa.cpp
+++ b/src/server/scripts/EasternKingdoms/MagistersTerrace/boss_priestess_delrissa.cpp
@@ -850,17 +850,12 @@ public:
             if (Blink_Timer <= diff)
             {
                 bool InMeleeRange = false;
-                ThreatContainer::StorageType const& t_list = me->GetThreatManager().getThreatList();
-                for (ThreatContainer::StorageType::const_iterator itr = t_list.begin(); itr!= t_list.end(); ++itr)
+                for (auto const& pair : me->GetCombatManager().GetPvECombatRefs())
                 {
-                    if (Unit* target = ObjectAccessor::GetUnit(*me, (*itr)->getUnitGuid()))
+                    if (pair.second->GetOther(me)->IsWithinMeleeRange(me))
                     {
-                        //if in melee range
-                        if (target->IsWithinDistInMap(me, 5))
-                        {
-                            InMeleeRange = true;
-                            break;
-                        }
+                        InMeleeRange = true;
+                        break;
                     }
                 }
 
@@ -944,17 +939,12 @@ public:
             if (Intercept_Stun_Timer <= diff)
             {
                 bool InMeleeRange = false;
-                ThreatContainer::StorageType const& t_list = me->GetThreatManager().getThreatList();
-                for (ThreatContainer::StorageType::const_iterator itr = t_list.begin(); itr!= t_list.end(); ++itr)
+                for (auto const& pair : me->GetCombatManager().GetPvECombatRefs())
                 {
-                    if (Unit* target = ObjectAccessor::GetUnit(*me, (*itr)->getUnitGuid()))
+                    if (pair.second->GetOther(me)->IsWithinMeleeRange(me))
                     {
-                        //if in melee range
-                        if (target->IsWithinDistInMap(me, ATTACK_DISTANCE))
-                        {
-                            InMeleeRange = true;
-                            break;
-                        }
+                        InMeleeRange = true;
+                        break;
                     }
                 }
 
diff --git a/src/server/scripts/EasternKingdoms/TheStockade/boss_randolph_moloch.cpp b/src/server/scripts/EasternKingdoms/TheStockade/boss_randolph_moloch.cpp
index 901a1522223..573d3c6a4d5 100644
--- a/src/server/scripts/EasternKingdoms/TheStockade/boss_randolph_moloch.cpp
+++ b/src/server/scripts/EasternKingdoms/TheStockade/boss_randolph_moloch.cpp
@@ -115,7 +115,6 @@ struct boss_randolph_moloch : public BossAI
                 me->RemoveAllAuras();
                 DoCastSelf(SPELL_VANISH);
                 me->SetReactState(REACT_PASSIVE);
-                me->SetInCombatState(true); // Prevents the boss from resetting
                 events.ScheduleEvent(EVENT_JUST_VANISHED, 2s);
                 break;
             case EVENT_JUST_VANISHED:
diff --git a/src/server/scripts/EasternKingdoms/ZulGurub/boss_mandokir.cpp b/src/server/scripts/EasternKingdoms/ZulGurub/boss_mandokir.cpp
index 5c63f224ff7..da7fff52dac 100644
--- a/src/server/scripts/EasternKingdoms/ZulGurub/boss_mandokir.cpp
+++ b/src/server/scripts/EasternKingdoms/ZulGurub/boss_mandokir.cpp
@@ -555,7 +555,7 @@ class DevastatingSlamTargetSelector : public std::unary_function<Unit *, bool>
 
         bool operator() (WorldObject* target)
         {
-            if (target == _victim && _me->GetThreatManager().getThreatList().size() > 1)
+            if (target == _victim && _me->GetThreatManager().GetThreatListSize() > 1)
                 return true;
 
             if (target->GetTypeId() != TYPEID_PLAYER)
@@ -684,7 +684,7 @@ class spell_mandokir_ohgan_orders_trigger : public SpellScriptLoader
                     caster->GetMotionMaster()->Clear();
                     caster->GetThreatManager().ClearAllThreat();
                     caster->GetThreatManager().AddThreat(target, 50000000.0f);
-                    caster->TauntApply(target);
+                    // TODO: Fixate mechanic
                 }
             }
 
diff --git a/src/server/scripts/Kalimdor/Firelands/boss_alysrazor.cpp b/src/server/scripts/Kalimdor/Firelands/boss_alysrazor.cpp
index 6c7f00f9b32..e0198304477 100644
--- a/src/server/scripts/Kalimdor/Firelands/boss_alysrazor.cpp
+++ b/src/server/scripts/Kalimdor/Firelands/boss_alysrazor.cpp
@@ -635,7 +635,7 @@ class spell_alysrazor_aggro_closest : public SpellScriptLoader
             void HandleEffect(SpellEffIndex effIndex)
             {
                 PreventHitDefaultEffect(effIndex);
-                float curThreat = GetCaster()->GetThreatManager().getThreat(GetHitUnit(), true);
+                float curThreat = GetCaster()->GetThreatManager().GetThreat(GetHitUnit(), true);
                 GetCaster()->GetThreatManager().AddThreat(GetHitUnit(), -curThreat + 50000.0f / std::min(1.0f, GetCaster()->GetDistance(GetHitUnit())));
             }
 
diff --git a/src/server/scripts/Kalimdor/Firelands/firelands.cpp b/src/server/scripts/Kalimdor/Firelands/firelands.cpp
index 572e9a02f9f..6367bc88611 100644
--- a/src/server/scripts/Kalimdor/Firelands/firelands.cpp
+++ b/src/server/scripts/Kalimdor/Firelands/firelands.cpp
@@ -233,7 +233,7 @@ struct npc_firelands_magmakin : public ScriptedAI
             return;
 
         AddThreat(target, 50000000.0f);
-        me->TauntApply(target);
+        // TODO: Fixate mechanic
     }
 
     void UpdateAI(uint32 /*diff*/) override
diff --git a/src/server/scripts/Maelstrom/Stonecore/boss_corborus.cpp b/src/server/scripts/Maelstrom/Stonecore/boss_corborus.cpp
index a491b553763..6824bc68385 100644
--- a/src/server/scripts/Maelstrom/Stonecore/boss_corborus.cpp
+++ b/src/server/scripts/Maelstrom/Stonecore/boss_corborus.cpp
@@ -267,13 +267,13 @@ class npc_rock_borer : public CreatureScript
             {
                 me->SetDisableGravity(true);
                 me->SetReactState(REACT_PASSIVE);
-                events.ScheduleEvent(EVENT_EMERGED, 1200);
-                events.ScheduleEvent(EVENT_ROCK_BORE, urand(15000, 20000)); // Need sniffs for this timer
             }
 
-            void IsSummonedBy(Unit* summoner) override
+            void IsSummonedBy(Unit* /*summoner*/) override
             {
-                me->SetInCombatState(false, summoner);
+                events.ScheduleEvent(EVENT_EMERGED, 1200);
+                events.ScheduleEvent(EVENT_ROCK_BORE, urand(15000, 20000)); // Need sniffs for this timer
+                DoZoneInCombat();
                 DoCast(me, SPELL_ROCK_BORER_EMERGE);
             }
 
diff --git a/src/server/scripts/Northrend/AzjolNerub/Ahnkahet/boss_prince_taldaram.cpp b/src/server/scripts/Northrend/AzjolNerub/Ahnkahet/boss_prince_taldaram.cpp
index 86632ed7e99..31d5a9a3e26 100644
--- a/src/server/scripts/Northrend/AzjolNerub/Ahnkahet/boss_prince_taldaram.cpp
+++ b/src/server/scripts/Northrend/AzjolNerub/Ahnkahet/boss_prince_taldaram.cpp
@@ -41,6 +41,7 @@ enum Spells
     SPELL_FLAME_SPHERE_DEATH_EFFECT         = 55947,
     SPELL_EMBRACE_OF_THE_VAMPYR             = 55959,
     SPELL_VANISH                            = 55964,
+    SPELL_SHADOWSTEP                        = 55966,
 
     NPC_FLAME_SPHERE_1                      = 30106,
     NPC_FLAME_SPHERE_2                      = 31686,
@@ -77,9 +78,8 @@ enum Events
     EVENT_CONJURE_FLAME_SPHERES             = 1,
     EVENT_BLOODTHIRST,
     EVENT_VANISH,
-    EVENT_JUST_VANISHED,
-    EVENT_VANISHED,
-    EVENT_FEEDING,
+    EVENT_START_FEEDING,
+    EVENT_DONE_FEEDING,
 
     // Flame Sphere
     EVENT_START_MOVE,
@@ -97,6 +97,7 @@ class boss_prince_taldaram : public CreatureScript
             {
                 me->SetDisableGravity(true);
                 _embraceTakenDamage = 0;
+                _initialCheckTimer = 3000;
             }
 
             void Reset() override
@@ -140,8 +141,30 @@ class boss_prince_taldaram : public CreatureScript
 
             void UpdateAI(uint32 diff) override
             {
-                if (!UpdateVictim())
-                    return;
+                if (_initialCheckTimer)
+                {
+                    if (_initialCheckTimer <= diff)
+                    {
+                        CheckSpheres();
+                        _initialCheckTimer = 0;
+                    }
+                    else
+                        _initialCheckTimer -= diff;
+                }
+
+                if (me->HasAura(SPELL_VANISH))
+                {
+                    if (me->GetThreatManager().IsThreatListEmpty(true))
+                    {
+                        EnterEvadeMode(EVADE_REASON_NO_HOSTILES);
+                        return;
+                    }
+                }
+                else
+                {
+                    if (!UpdateVictim())
+                        return;
+                }
 
                 events.Update(diff);
 
@@ -167,47 +190,29 @@ class boss_prince_taldaram : public CreatureScript
                             break;
                         case EVENT_VANISH:
                         {
-                            Map::PlayerList const& players = me->GetMap()->GetPlayers();
-                            uint32 targets = 0;
-                            for (Map::PlayerList::const_iterator i = players.begin(); i != players.end(); ++i)
-                            {
-                                Player* player = i->GetSource();
-                                if (player && player->IsAlive())
-                                    ++targets;
-                            }
-
-                            if (targets > 2)
+                            if (me->GetThreatManager().GetThreatListSize() > 1)
                             {
+                                if (Unit* embraceTarget = SelectTarget(SELECT_TARGET_RANDOM, 0, 100.0f, true))
+                                    _embraceTargetGUID = embraceTarget->GetGUID();
                                 Talk(SAY_VANISH);
                                 DoCast(me, SPELL_VANISH);
-                                me->SetInCombatState(true); // Prevents the boss from resetting
                                 events.DelayEvents(500);
-                                events.ScheduleEvent(EVENT_JUST_VANISHED, 500);
-                                if (Unit* embraceTarget = SelectTarget(SELECT_TARGET_RANDOM, 0, 100.0f, true))
-                                    _embraceTargetGUID = embraceTarget->GetGUID();
+                                events.ScheduleEvent(EVENT_START_FEEDING, 2000);
                             }
                             events.ScheduleEvent(EVENT_VANISH, urand(25000, 35000));
                             break;
                         }
-                        case EVENT_JUST_VANISHED:
+                        case EVENT_START_FEEDING:
+                            me->RemoveAurasDueToSpell(SPELL_VANISH);
                             if (Unit* embraceTarget = GetEmbraceTarget())
                             {
-                                me->GetMotionMaster()->Clear();
-                                me->SetSpeedRate(MOVE_WALK, 2.0f);
-                                me->GetMotionMaster()->MoveChase(embraceTarget);
-                            }
-                            events.ScheduleEvent(EVENT_VANISHED, 1300);
-                            break;
-                        case EVENT_VANISHED:
-                            if (Unit* embraceTarget = GetEmbraceTarget())
+                                DoCast(embraceTarget, SPELL_SHADOWSTEP);
                                 DoCast(embraceTarget, SPELL_EMBRACE_OF_THE_VAMPYR);
-                            Talk(SAY_FEED);
-                            me->GetMotionMaster()->Clear();
-                            me->SetSpeedRate(MOVE_WALK, 1.0f);
-                            me->GetMotionMaster()->MoveChase(me->GetVictim());
-                            events.ScheduleEvent(EVENT_FEEDING, 20000);
+                                Talk(SAY_FEED);
+                                events.ScheduleEvent(EVENT_DONE_FEEDING, 20000);
+                            }
                             break;
-                        case EVENT_FEEDING:
+                        case EVENT_DONE_FEEDING:
                             _embraceTargetGUID.Clear();
                             break;
                         default:
@@ -289,6 +294,7 @@ class boss_prince_taldaram : public CreatureScript
             ObjectGuid _flameSphereTargetGUID;
             ObjectGuid _embraceTargetGUID;
             uint32 _embraceTakenDamage;
+            uint32 _initialCheckTimer;
         };
 
         CreatureAI* GetAI(Creature* creature) const override
diff --git a/src/server/scripts/Northrend/AzjolNerub/AzjolNerub/boss_hadronox.cpp b/src/server/scripts/Northrend/AzjolNerub/AzjolNerub/boss_hadronox.cpp
index 7b3946364bb..9f99e018345 100644
--- a/src/server/scripts/Northrend/AzjolNerub/AzjolNerub/boss_hadronox.cpp
+++ b/src/server/scripts/Northrend/AzjolNerub/AzjolNerub/boss_hadronox.cpp
@@ -163,13 +163,9 @@ public:
 
         bool IsInCombatWithPlayer() const
         {
-            std::list<HostileReference*> const& refs = me->GetThreatManager().getThreatList();
-            for (HostileReference const* hostileRef : refs)
-            {
-                if (Unit const* target = hostileRef->getTarget())
-                    if (target->IsControlledByPlayer())
-                        return true;
-            }
+            for (auto const& pair : me->GetCombatManager().GetPvECombatRefs())
+                if (pair.second->GetOther(me)->IsControlledByPlayer())
+                    return true;
             return false;
         }
 
diff --git a/src/server/scripts/Northrend/CrusadersColiseum/TrialOfTheCrusader/boss_anubarak_trial.cpp b/src/server/scripts/Northrend/CrusadersColiseum/TrialOfTheCrusader/boss_anubarak_trial.cpp
index dea9b160e08..7ea2afc6e84 100644
--- a/src/server/scripts/Northrend/CrusadersColiseum/TrialOfTheCrusader/boss_anubarak_trial.cpp
+++ b/src/server/scripts/Northrend/CrusadersColiseum/TrialOfTheCrusader/boss_anubarak_trial.cpp
@@ -820,7 +820,7 @@ class npc_anubarak_spike : public CreatureScript
                 DoCast(who, SPELL_MARK);
                 me->SetSpeedRate(MOVE_RUN, 0.5f);
                 // make sure the Spine will really follow the one he should
-                ResetThreatList();
+                me->GetThreatManager().ResetAllThreat();
                 me->SetInCombatWithZone();
                 AddThreat(who, 1000000.0f);
                 me->GetMotionMaster()->Clear(true);
diff --git a/src/server/scripts/Northrend/CrusadersColiseum/TrialOfTheCrusader/boss_faction_champions.cpp b/src/server/scripts/Northrend/CrusadersColiseum/TrialOfTheCrusader/boss_faction_champions.cpp
index 1adc7eb9abf..658d4bb80a6 100644
--- a/src/server/scripts/Northrend/CrusadersColiseum/TrialOfTheCrusader/boss_faction_champions.cpp
+++ b/src/server/scripts/Northrend/CrusadersColiseum/TrialOfTheCrusader/boss_faction_champions.cpp
@@ -672,14 +672,10 @@ struct boss_faction_championsAI : public BossAI
 
     Unit* SelectEnemyCaster(bool /*casting*/)
     {
-        std::list<HostileReference*> const& tList = me->GetThreatManager().getThreatList();
-        std::list<HostileReference*>::const_iterator iter;
-        for (iter = tList.begin(); iter!=tList.end(); ++iter)
-        {
-            Unit* target = ObjectAccessor::GetUnit(*me, (*iter)->getUnitGuid());
-            if (target && target->GetPowerType() == POWER_MANA)
-                return target;
-        }
+        for (auto const& pair : me->GetCombatManager().GetPvECombatRefs())
+            if (Player* player = pair.second->GetOther(me)->ToPlayer())
+                if (player->GetPowerType() == POWER_MANA)
+                    return player;
         return nullptr;
     }
 
diff --git a/src/server/scripts/Northrend/FrozenHalls/HallsOfReflection/halls_of_reflection.cpp b/src/server/scripts/Northrend/FrozenHalls/HallsOfReflection/halls_of_reflection.cpp
index 29cb72ebb40..93fe8951d72 100644
--- a/src/server/scripts/Northrend/FrozenHalls/HallsOfReflection/halls_of_reflection.cpp
+++ b/src/server/scripts/Northrend/FrozenHalls/HallsOfReflection/halls_of_reflection.cpp
@@ -1342,7 +1342,7 @@ class npc_the_lich_king_escape_hor : public CreatureScript
                             AttackStart(victim);
                     return me->GetVictim() != nullptr;
                 }
-                else if (me->GetThreatManager().GetThreatListSize() < 2 && me->HasAura(SPELL_REMORSELESS_WINTER))
+                else if (me->GetCombatManager().GetPvECombatRefs().size() < 2 && me->HasAura(SPELL_REMORSELESS_WINTER))
                 {
                     EnterEvadeMode(EVADE_REASON_OTHER);
                     return false;
diff --git a/src/server/scripts/Northrend/Gundrak/boss_drakkari_colossus.cpp b/src/server/scripts/Northrend/Gundrak/boss_drakkari_colossus.cpp
index 938d3701368..b6cebf1c172 100644
--- a/src/server/scripts/Northrend/Gundrak/boss_drakkari_colossus.cpp
+++ b/src/server/scripts/Northrend/Gundrak/boss_drakkari_colossus.cpp
@@ -148,15 +148,12 @@ class boss_drakkari_colossus : public CreatureScript
                         if (me->GetReactState() == REACT_AGGRESSIVE)
                             return;
 
-                        me->SetReactState(REACT_AGGRESSIVE);
                         me->SetImmuneToPC(false);
+                        me->SetReactState(REACT_AGGRESSIVE);
                         me->RemoveAura(SPELL_FREEZE_ANIM);
 
                         me->SetInCombatWithZone();
 
-                        if (me->GetVictim())
-                            me->GetMotionMaster()->MoveChase(me->GetVictim(), 0, 0);
-
                         break;
                 }
             }
diff --git a/src/server/scripts/Northrend/IcecrownCitadel/boss_valithria_dreamwalker.cpp b/src/server/scripts/Northrend/IcecrownCitadel/boss_valithria_dreamwalker.cpp
index a80874a211e..01213a9009d 100644
--- a/src/server/scripts/Northrend/IcecrownCitadel/boss_valithria_dreamwalker.cpp
+++ b/src/server/scripts/Northrend/IcecrownCitadel/boss_valithria_dreamwalker.cpp
@@ -559,25 +559,15 @@ class npc_green_dragon_combat_trigger : public CreatureScript
                 if (!me->IsInCombat())
                     return;
 
-                // @TODO check out of bounds on all encounter creatures, evade if matched
-
-                std::list<HostileReference*> const& threatList = me->GetThreatManager().getThreatList();
-                if (threatList.empty())
-                {
-                    EnterEvadeMode();
-                    return;
-                }
-
                 // check evade every second tick
                 _evadeCheck ^= true;
                 if (!_evadeCheck)
                     return;
 
-                // check if there is any player on threatlist, if not - evade
-                for (std::list<HostileReference*>::const_iterator itr = threatList.begin(); itr != threatList.end(); ++itr)
-                    if (Unit* target = (*itr)->getTarget())
-                        if (target->GetTypeId() == TYPEID_PLAYER)
-                            return; // found any player, return
+                // check if there is any player engaged, if not - evade
+                for (auto const& pair : me->GetCombatManager().GetPvECombatRefs())
+                    if (pair.second->GetOther(me)->GetTypeId() == TYPEID_PLAYER)
+                        return;
 
                 EnterEvadeMode();
             }
diff --git a/src/server/scripts/Northrend/Ulduar/Ulduar/boss_hodir.cpp b/src/server/scripts/Northrend/Ulduar/Ulduar/boss_hodir.cpp
index 8ddc4d1a7dc..8737e8a2425 100644
--- a/src/server/scripts/Northrend/Ulduar/Ulduar/boss_hodir.cpp
+++ b/src/server/scripts/Northrend/Ulduar/Ulduar/boss_hodir.cpp
@@ -489,12 +489,11 @@ class boss_hodir : public CreatureScript
 
                 if (gettingColdInHereTimer <= diff && gettingColdInHere)
                 {
-                    std::list<HostileReference*> ThreatList = me->GetThreatManager().getThreatList();
-                    for (std::list<HostileReference*>::const_iterator itr = ThreatList.begin(); itr != ThreatList.end(); ++itr)
-                        if (Unit* target = ObjectAccessor::GetUnit(*me, (*itr)->getUnitGuid()))
+                    for (auto const& pair : me->GetCombatManager().GetPvECombatRefs())
+                        if (Player* target = pair.second->GetOther(me)->ToPlayer())
                             if (Aura* BitingColdAura = target->GetAura(SPELL_BITING_COLD_TRIGGERED))
-                                if ((target->GetTypeId() == TYPEID_PLAYER) && (BitingColdAura->GetStackAmount() > 2))
-                                        SetData(DATA_GETTING_COLD_IN_HERE, 0);
+                                if (BitingColdAura->GetStackAmount() > 2)
+                                    SetData(DATA_GETTING_COLD_IN_HERE, 0);
                     gettingColdInHereTimer = 1000;
                 }
                 else
diff --git a/src/server/scripts/Northrend/UtgardeKeep/UtgardeKeep/boss_ingvar_the_plunderer.cpp b/src/server/scripts/Northrend/UtgardeKeep/UtgardeKeep/boss_ingvar_the_plunderer.cpp
index f3b6d1af83e..7dd7fe30571 100644
--- a/src/server/scripts/Northrend/UtgardeKeep/UtgardeKeep/boss_ingvar_the_plunderer.cpp
+++ b/src/server/scripts/Northrend/UtgardeKeep/UtgardeKeep/boss_ingvar_the_plunderer.cpp
@@ -198,7 +198,7 @@ class boss_ingvar_the_plunderer : public CreatureScript
 
             void UpdateAI(uint32 diff) override
             {
-                if (!events.IsInPhase(PHASE_EVENT) && !UpdateVictim())
+                if (!UpdateVictim())
                     return;
 
                 events.Update(diff);
@@ -231,9 +231,7 @@ class boss_ingvar_the_plunderer : public CreatureScript
                             ScheduleSecondPhase();
                             me->RemoveUnitFlag(UnitFlags(UNIT_FLAG_NON_ATTACKABLE | UNIT_FLAG_NOT_SELECTABLE));
                             me->SetImmuneToPC(false);
-                            if (Unit* target = me->GetThreatManager().SelectVictim())
-                                AttackStart(target);
-                            else
+                            if (!me->IsThreatened())
                             {
                                 EnterEvadeMode(EVADE_REASON_NO_HOSTILES);
                                 return;
diff --git a/src/server/scripts/Northrend/VaultOfArchavon/boss_toravon.cpp b/src/server/scripts/Northrend/VaultOfArchavon/boss_toravon.cpp
index 748e04ba3d0..2ab98e53093 100644
--- a/src/server/scripts/Northrend/VaultOfArchavon/boss_toravon.cpp
+++ b/src/server/scripts/Northrend/VaultOfArchavon/boss_toravon.cpp
@@ -184,7 +184,7 @@ class spell_toravon_random_aggro : public SpellScript
         if (!caster->IsAIEnabled)
             return;
 
-        caster->GetThreatManager().resetAllAggro();
+        caster->GetThreatManager().ResetAllThreat();
 
         if (Unit* target = caster->AI()->SelectTarget(SELECT_TARGET_RANDOM, 1))
             caster->GetThreatManager().AddThreat(target, 1000000);
diff --git a/src/server/scripts/Spells/spell_hunter.cpp b/src/server/scripts/Spells/spell_hunter.cpp
index 45a8e390b9c..ed8f1eb38d5 100644
--- a/src/server/scripts/Spells/spell_hunter.cpp
+++ b/src/server/scripts/Spells/spell_hunter.cpp
@@ -38,6 +38,7 @@ enum HunterSpells
     SPELL_HUNTER_EXHILARATION_R2                    = 231546,
     SPELL_HUNTER_LONE_WOLF                          = 155228,
     SPELL_HUNTER_MASTERS_CALL_TRIGGERED             = 62305,
+    SPELL_HUNTER_MISDIRECTION                       = 34477,
     SPELL_HUNTER_MISDIRECTION_PROC                  = 35079,
     SPELL_HUNTER_MULTI_SHOT_FOCUS                   = 213363,
     SPELL_HUNTER_PET_LAST_STAND_TRIGGERED           = 53479,
@@ -297,12 +298,7 @@ class spell_hun_misdirection : public SpellScriptLoader
                     return;
 
                 if (!GetTarget()->HasAura(SPELL_HUNTER_MISDIRECTION_PROC))
-                    GetTarget()->ResetRedirectThreat();
-            }
-
-            bool CheckProc(ProcEventInfo& /*eventInfo*/)
-            {
-                return GetTarget()->GetRedirectThreatTarget() != nullptr;
+                    GetTarget()->GetThreatManager().UnregisterRedirectThreat(SPELL_HUNTER_MISDIRECTION);
             }
 
             void HandleProc(AuraEffect* aurEff, ProcEventInfo& /*eventInfo*/)
@@ -314,7 +310,6 @@ class spell_hun_misdirection : public SpellScriptLoader
             void Register() override
             {
                 AfterEffectRemove += AuraEffectRemoveFn(spell_hun_misdirection_AuraScript::OnRemove, EFFECT_1, SPELL_AURA_DUMMY, AURA_EFFECT_HANDLE_REAL);
-                DoCheckProc += AuraCheckProcFn(spell_hun_misdirection_AuraScript::CheckProc);
                 OnEffectProc += AuraEffectProcFn(spell_hun_misdirection_AuraScript::HandleProc, EFFECT_1, SPELL_AURA_DUMMY);
             }
         };
@@ -337,7 +332,7 @@ class spell_hun_misdirection_proc : public SpellScriptLoader
 
             void OnRemove(AuraEffect const* /*aurEff*/, AuraEffectHandleModes /*mode*/)
             {
-                GetTarget()->ResetRedirectThreat();
+                GetTarget()->GetThreatManager().UnregisterRedirectThreat(SPELL_HUNTER_MISDIRECTION);
             }
 
             void Register() override
diff --git a/src/server/scripts/Spells/spell_rogue.cpp b/src/server/scripts/Spells/spell_rogue.cpp
index 003b55c260e..25ba6f0006d 100644
--- a/src/server/scripts/Spells/spell_rogue.cpp
+++ b/src/server/scripts/Spells/spell_rogue.cpp
@@ -51,6 +51,7 @@ enum RogueSpells
     SPELL_ROGUE_STEALTH_STEALTH_AURA                = 158185,
     SPELL_ROGUE_STEALTH_SHAPESHIFT_AURA             = 158188,
     SPELL_ROGUE_VANISH_AURA                         = 11327,
+    SPELL_ROGUE_TRICKS_OF_THE_TRADE                 = 57934,
     SPELL_ROGUE_TRICKS_OF_THE_TRADE_PROC            = 59628,
     SPELL_ROGUE_HONOR_AMONG_THIEVES_ENERGIZE        = 51699,
     SPELL_ROGUE_T5_2P_SET_BONUS                     = 37169
@@ -507,82 +508,78 @@ class spell_rog_vanish_aura : public SpellScriptLoader
 };
 
 // 57934 - Tricks of the Trade
-class spell_rog_tricks_of_the_trade : public SpellScriptLoader
+class spell_rog_tricks_of_the_trade_aura : public AuraScript
 {
-    public:
-        spell_rog_tricks_of_the_trade() : SpellScriptLoader("spell_rog_tricks_of_the_trade") { }
+    PrepareAuraScript(spell_rog_tricks_of_the_trade_aura);
 
-        class spell_rog_tricks_of_the_trade_AuraScript : public AuraScript
-        {
-            PrepareAuraScript(spell_rog_tricks_of_the_trade_AuraScript);
+    bool Validate(SpellInfo const* /*spellInfo*/) override
+    {
+        return ValidateSpellInfo({ SPELL_ROGUE_TRICKS_OF_THE_TRADE_PROC });
+    }
 
-            bool Validate(SpellInfo const* /*spellInfo*/) override
-            {
-                return ValidateSpellInfo({ SPELL_ROGUE_TRICKS_OF_THE_TRADE_PROC });
-            }
+    void OnRemove(AuraEffect const* /*aurEff*/, AuraEffectHandleModes /*mode*/)
+    {
+        if (GetTargetApplication()->GetRemoveMode() != AURA_REMOVE_BY_DEFAULT || !GetTarget()->HasAura(SPELL_ROGUE_TRICKS_OF_THE_TRADE_PROC))
+            GetTarget()->GetThreatManager().UnregisterRedirectThreat(SPELL_ROGUE_TRICKS_OF_THE_TRADE);
+    }
 
-            void OnRemove(AuraEffect const* /*aurEff*/, AuraEffectHandleModes /*mode*/)
-            {
-                if (GetTargetApplication()->GetRemoveMode() != AURA_REMOVE_BY_DEFAULT)
-                    GetTarget()->ResetRedirectThreat();
-            }
+    void HandleProc(AuraEffect* aurEff, ProcEventInfo& /*eventInfo*/)
+    {
+        PreventDefaultAction();
 
-            bool CheckProc(ProcEventInfo& /*eventInfo*/)
-            {
-                _redirectTarget = GetTarget()->GetRedirectThreatTarget();
-                return _redirectTarget != nullptr;
-            }
+        Unit* rogue = GetTarget();
+        if (ObjectAccessor::GetUnit(*rogue, _redirectTarget))
+            rogue->CastSpell(rogue, SPELL_ROGUE_TRICKS_OF_THE_TRADE_PROC, aurEff);
+        Remove(AURA_REMOVE_BY_DEFAULT);
+    }
 
-            void HandleProc(AuraEffect* /*aurEff*/, ProcEventInfo& /*eventInfo*/)
-            {
-                PreventDefaultAction();
+    void Register() override
+    {
+        AfterEffectRemove += AuraEffectRemoveFn(spell_rog_tricks_of_the_trade_aura::OnRemove, EFFECT_1, SPELL_AURA_DUMMY, AURA_EFFECT_HANDLE_REAL);
+        OnEffectProc += AuraEffectProcFn(spell_rog_tricks_of_the_trade_aura::HandleProc, EFFECT_1, SPELL_AURA_DUMMY);
+    }
 
-                Unit* target = GetTarget();
-                target->CastSpell(target, SPELL_ROGUE_TRICKS_OF_THE_TRADE_PROC, true);
-                Remove(AURA_REMOVE_BY_DEFAULT); // maybe handle by proc charges
-            }
+    ObjectGuid _redirectTarget;
+public:
+    void SetRedirectTarget(ObjectGuid guid) { _redirectTarget = guid; }
+};
 
-            void Register() override
+class spell_rog_tricks_of_the_trade : public SpellScript
+{
+    PrepareSpellScript(spell_rog_tricks_of_the_trade);
+
+    void DoAfterHit()
+    {
+        if (Aura* aura = GetHitAura())
+            if (auto* script = aura->GetScript<spell_rog_tricks_of_the_trade_aura>("spell_rog_tricks_of_the_trade"))
             {
-                AfterEffectRemove += AuraEffectRemoveFn(spell_rog_tricks_of_the_trade_AuraScript::OnRemove, EFFECT_1, SPELL_AURA_DUMMY, AURA_EFFECT_HANDLE_REAL);
-                DoCheckProc += AuraCheckProcFn(spell_rog_tricks_of_the_trade_AuraScript::CheckProc);
-                OnEffectProc += AuraEffectProcFn(spell_rog_tricks_of_the_trade_AuraScript::HandleProc, EFFECT_1, SPELL_AURA_DUMMY);
+                if (Unit* explTarget = GetExplTargetUnit())
+                    script->SetRedirectTarget(explTarget->GetGUID());
+                else
+                    script->SetRedirectTarget(ObjectGuid::Empty);
             }
+    }
 
-            Unit* _redirectTarget = nullptr;
-        };
-
-        AuraScript* GetAuraScript() const override
-        {
-            return new spell_rog_tricks_of_the_trade_AuraScript();
-        }
+    void Register() override
+    {
+        AfterHit += SpellHitFn(spell_rog_tricks_of_the_trade::DoAfterHit);
+    }
 };
 
 // 59628 - Tricks of the Trade (Proc)
-class spell_rog_tricks_of_the_trade_proc : public SpellScriptLoader
+class spell_rog_tricks_of_the_trade_proc : public AuraScript
 {
-    public:
-        spell_rog_tricks_of_the_trade_proc() : SpellScriptLoader("spell_rog_tricks_of_the_trade_proc") { }
+    PrepareAuraScript(spell_rog_tricks_of_the_trade_proc);
 
-        class spell_rog_tricks_of_the_trade_proc_AuraScript : public AuraScript
-        {
-            PrepareAuraScript(spell_rog_tricks_of_the_trade_proc_AuraScript);
-
-            void HandleRemove(AuraEffect const* /*aurEff*/, AuraEffectHandleModes /*mode*/)
-            {
-                GetTarget()->ResetRedirectThreat();
-            }
-
-            void Register() override
-            {
-                AfterEffectRemove += AuraEffectRemoveFn(spell_rog_tricks_of_the_trade_proc_AuraScript::HandleRemove, EFFECT_0, SPELL_AURA_DUMMY, AURA_EFFECT_HANDLE_REAL);
-            }
-        };
+    void HandleRemove(AuraEffect const* /*aurEff*/, AuraEffectHandleModes /*mode*/)
+    {
+        GetTarget()->GetThreatManager().UnregisterRedirectThreat(SPELL_ROGUE_TRICKS_OF_THE_TRADE);
+    }
 
-        AuraScript* GetAuraScript() const override
-        {
-            return new spell_rog_tricks_of_the_trade_proc_AuraScript();
-        }
+    void Register() override
+    {
+        AfterEffectRemove += AuraEffectRemoveFn(spell_rog_tricks_of_the_trade_proc::HandleRemove, EFFECT_0, SPELL_AURA_DUMMY, AURA_EFFECT_HANDLE_REAL);
+    }
 };
 
 // 198031 - Honor Among Thieves
@@ -704,8 +701,8 @@ void AddSC_rogue_spell_scripts()
     new spell_rog_stealth();
     new spell_rog_vanish();
     new spell_rog_vanish_aura();
-    new spell_rog_tricks_of_the_trade();
-    new spell_rog_tricks_of_the_trade_proc();
+    RegisterSpellAndAuraScriptPair(spell_rog_tricks_of_the_trade, spell_rog_tricks_of_the_trade_aura);
+    RegisterAuraScript(spell_rog_tricks_of_the_trade_proc);
     new spell_rog_honor_among_thieves();
     new spell_rog_eviscerate();
     new spell_rog_envenom();
diff --git a/src/server/scripts/Spells/spell_warlock.cpp b/src/server/scripts/Spells/spell_warlock.cpp
index 163c867d71d..1740f3291f9 100644
--- a/src/server/scripts/Spells/spell_warlock.cpp
+++ b/src/server/scripts/Spells/spell_warlock.cpp
@@ -51,7 +51,7 @@ enum WarlockSpells
     SPELL_WARLOCK_RAIN_OF_FIRE_DAMAGE               = 42223,
     SPELL_WARLOCK_SEED_OF_CORRUPTION_DAMAGE         = 27285,
     SPELL_WARLOCK_SEED_OF_CORRUPTION_GENERIC        = 32865,
-    SPELL_WARLOCK_SOULSHATTER                       = 32835,
+    SPELL_WARLOCK_SOULSHATTER_EFFECT                = 32835,
     SPELL_WARLOCK_SOUL_SWAP_CD_MARKER               = 94229,
     SPELL_WARLOCK_SOUL_SWAP_OVERRIDE                = 86211,
     SPELL_WARLOCK_SOUL_SWAP_MOD_COST                = 92794,
@@ -815,15 +815,15 @@ class spell_warl_soulshatter : public SpellScriptLoader
 
             bool Validate(SpellInfo const* /*spellInfo*/) override
             {
-                return ValidateSpellInfo({ SPELL_WARLOCK_SOULSHATTER });
+                return ValidateSpellInfo({ SPELL_WARLOCK_SOULSHATTER_EFFECT });
             }
 
             void HandleDummy(SpellEffIndex /*effIndex*/)
             {
                 Unit* caster = GetCaster();
                 if (Unit* target = GetHitUnit())
-                    if (target->CanHaveThreatList() && target->GetThreatManager().IsThreatenedBy(caster, true))
-                        caster->CastSpell(target, SPELL_WARLOCK_SOULSHATTER, true);
+                    if (target->GetThreatManager().IsThreatenedBy(caster, true))
+                        caster->CastSpell(target, SPELL_WARLOCK_SOULSHATTER_EFFECT, true);
             }
 
             void Register() override
diff --git a/src/server/scripts/World/npcs_special.cpp b/src/server/scripts/World/npcs_special.cpp
index 3c8dac9d8de..0591f7c4a76 100644
--- a/src/server/scripts/World/npcs_special.cpp
+++ b/src/server/scripts/World/npcs_special.cpp
@@ -1806,21 +1806,28 @@ public:
                 {
                     case EVENT_TD_CHECK_COMBAT:
                     {
-                        time_t now = GameTime::GetGameTime();
-                        for (std::unordered_map<ObjectGuid, time_t>::iterator itr = _damageTimes.begin(); itr != _damageTimes.end();)
+                        time_t const now = GameTime::GetGameTime();
+                        auto const& pveRefs = me->GetCombatManager().GetPvECombatRefs();
+                        for (auto itr = _damageTimes.begin(); itr != _damageTimes.end();)
                         {
                             // If unit has not dealt damage to training dummy for 5 seconds, remove him from combat
                             if (itr->second < now - 5)
                             {
-                                if (Unit* unit = ObjectAccessor::GetUnit(*me, itr->first))
-                                    unit->getHostileRefManager().deleteReference(me);
+                                auto it = pveRefs.find(itr->first);
+                                if (it != pveRefs.end())
+                                    it->second->EndCombat();
 
                                 itr = _damageTimes.erase(itr);
                             }
                             else
                                 ++itr;
                         }
-                        _events.ScheduleEvent(EVENT_TD_CHECK_COMBAT, 1000);
+
+                        for (auto const& pair : pveRefs)
+                            if (_damageTimes.find(pair.first) == _damageTimes.end())
+                                _damageTimes[pair.first] = now;
+
+                        _events.Repeat(1s);
                         break;
                     }
                     case EVENT_TD_DESPAWN: