2 files changed, 37 insertions, 18 deletions

diff --git a/src/common/Utilities/EventProcessor.h b/src/common/Utilities/EventProcessor.h
index 11ca046bd18..8da9c47a19f 100644
--- a/src/common/Utilities/EventProcessor.h
+++ b/src/common/Utilities/EventProcessor.h
@@ -20,8 +20,9 @@
 
 #include "Define.h"
 #include "Duration.h"
-#include <map>
 #include "Random.h"
+#include "advstd.h"
+#include <map>
 
 class EventProcessor;
 
@@ -69,6 +70,26 @@ class TC_COMMON_API BasicEvent
         uint64 m_execTime;                                  // planned time of next execution, filled by event handler
 };
 
+template<typename T>
+class LambdaBasicEvent : public BasicEvent
+{
+public:
+    LambdaBasicEvent(T&& callback) : BasicEvent(), _callback(std::move(callback)) { }
+
+    bool Execute(uint64, uint32) override
+    {
+        _callback();
+        return true;
+    }
+
+private:
+
+    T _callback;
+};
+
+template<typename T>
+using is_lambda_event = std::enable_if_t<!advstd::is_base_of_v<BasicEvent, std::remove_pointer_t<advstd::remove_cvref_t<T>>>>;
+
 class TC_COMMON_API EventProcessor
 {
     public:
@@ -78,8 +99,14 @@ class TC_COMMON_API EventProcessor
         void Update(uint32 p_time);
         void KillAllEvents(bool force);
         void AddEvent(BasicEvent* event, uint64 e_time, bool set_addtime = true);
+        template<typename T>
+        is_lambda_event<T> AddEvent(T&& event, uint64 e_time, bool set_addtime = true) { AddEvent(new LambdaBasicEvent<T>(std::move(event)), e_time, set_addtime); }
         void AddEventAtOffset(BasicEvent* event, Milliseconds offset) { AddEvent(event, CalculateTime(offset.count())); }
         void AddEventAtOffset(BasicEvent* event, Milliseconds offset, Milliseconds offset2) { AddEvent(event, CalculateTime(urand(offset.count(), offset2.count()))); }
+        template<typename T>
+        is_lambda_event<T> AddEventAtOffset(T&& event, Milliseconds offset) { AddEventAtOffset(new LambdaBasicEvent<T>(std::move(event)), offset); }
+        template<typename T>
+        is_lambda_event<T> AddEventAtOffset(T&& event, Milliseconds offset, Milliseconds offset2) { AddEventAtOffset(new LambdaBasicEvent<T>(std::move(event)), offset, offset2); }
         void ModifyEventTime(BasicEvent* event, uint64 newTime);
         uint64 CalculateTime(uint64 t_offset) const { return m_time + t_offset; }
         std::multimap<uint64, BasicEvent*> const& GetEvents() const { return m_events; }
diff --git a/src/server/scripts/EasternKingdoms/MagistersTerrace/boss_felblood_kaelthas.cpp b/src/server/scripts/EasternKingdoms/MagistersTerrace/boss_felblood_kaelthas.cpp
index 90bc62d3b12..85592df25cd 100644
--- a/src/server/scripts/EasternKingdoms/MagistersTerrace/boss_felblood_kaelthas.cpp
+++ b/src/server/scripts/EasternKingdoms/MagistersTerrace/boss_felblood_kaelthas.cpp
@@ -127,22 +127,6 @@ enum Phases
     PHASE_OUTRO = 3
 };
 
-class GravityElapseKnockupEvent : public BasicEvent
-{
-    public:
-        GravityElapseKnockupEvent(Unit* caster, uint32 difficultySpellId) :  _caster(caster), _difficultySpellId(difficultySpellId) { }
-
-        bool Execute(uint64 /*time*/, uint32 /*diff*/) override
-        {
-            _caster->CastSpell(_caster, _difficultySpellId);
-            _caster->CastSpell(_caster, SPELL_GRAVITY_LAPSE_FLY);
-            return true;
-        }
-    private:
-        Unit* _caster;
-        uint32 _difficultySpellId;
-};
-
 struct boss_felblood_kaelthas : public BossAI
 {
     boss_felblood_kaelthas(Creature* creature) : BossAI(creature, DATA_KAELTHAS_SUNSTRIDER)
@@ -238,10 +222,18 @@ struct boss_felblood_kaelthas : public BossAI
         switch (spell->Id)
         {
             case SPELL_GRAVITY_LAPSE_INITIAL:
+            {
                 DoCast(target, gravityLapseTeleportSpells[_gravityLapseTargetCount], true);
-                target->m_Events.AddEventAtOffset(new GravityElapseKnockupEvent(target, SPELL_GRAVITY_LAPSE_DAMAGE), 400ms);
+                uint32 gravityLapseDamageSpell = SPELL_GRAVITY_LAPSE_DAMAGE;
+                target->m_Events.AddEventAtOffset([target, gravityLapseDamageSpell]()
+                {
+                    target->CastSpell(target, gravityLapseDamageSpell);
+                    target->CastSpell(target, SPELL_GRAVITY_LAPSE_FLY);
+
+                }, 400ms);
                 _gravityLapseTargetCount++;
                 break;
+            }
             case SPELL_CLEAR_FLIGHT:
                 target->RemoveAurasDueToSpell(SPELL_GRAVITY_LAPSE_FLY);
                 target->RemoveAurasDueToSpell(SPELL_GRAVITY_LAPSE_DAMAGE);