diff --git a/sql/updates/world/custom/custom_2018_07_01_01_world.sql b/sql/updates/world/custom/custom_2018_07_01_01_world.sql
new file mode 100644
index 00000000000..a269c66758e
--- /dev/null
+++ b/sql/updates/world/custom/custom_2018_07_01_01_world.sql
@@ -0,0 +1 @@
+UPDATE `creature_template` SET `unit_flags`= `unit_flags` & ~33554688 WHERE `entry` IN (43214, 49538, 43438, 49642);
diff --git a/src/server/scripts/Maelstrom/Stonecore/boss_corborus.cpp b/src/server/scripts/Maelstrom/Stonecore/boss_corborus.cpp
index 06bbbe06bd3..72a7da23c16 100644
--- a/src/server/scripts/Maelstrom/Stonecore/boss_corborus.cpp
+++ b/src/server/scripts/Maelstrom/Stonecore/boss_corborus.cpp
@@ -110,6 +110,9 @@ class boss_corborus : public CreatureScript
             {
                 _Reset();
                 _countTrashingCharge = 0;
+
+                if (stateIntro != DONE)
+                    me->SetFlag(UNIT_FIELD_FLAGS, UNIT_FLAG_IMMUNE_TO_PC | UNIT_FLAG_NOT_SELECTABLE);
             }
 
             void JustEngagedWith(Unit* /*who*/) override
@@ -126,6 +129,7 @@ class boss_corborus : public CreatureScript
                 instance->SendEncounterUnit(ENCOUNTER_FRAME_DISENGAGE, me);
                 _EnterEvadeMode();
                 _DespawnAtEvade();
+                me->SetPosition(CorborusHomePos);
             }
 
             void JustDied(Unit* /*killer*/) override
@@ -194,7 +198,7 @@ class boss_corborus : public CreatureScript
                             // Make Corborus charge
                             DoCast(me, SPELL_RING_WYRM_CHARGE, true);
 
-                            events.ScheduleEvent(EVENT_CORBORUS_KNOCKBACK, 1000);
+                            events.ScheduleEvent(EVENT_CORBORUS_KNOCKBACK, Seconds(1));
                             break;
                         case EVENT_CORBORUS_KNOCKBACK:
                             // Spawn Twilight Documents (quest gameobject)
@@ -210,7 +214,7 @@ class boss_corborus : public CreatureScript
                             // Face Corborus to players and set new home position
                             me->SetFacingTo(3.176499f);
                             me->SetHomePosition(CorborusHomePos);
-                            me->RemoveFlag(UNIT_FIELD_FLAGS, UNIT_FLAG_IMMUNE_TO_PC);
+                            me->RemoveFlag(UNIT_FIELD_FLAGS, UNIT_FLAG_IMMUNE_TO_PC | UNIT_FLAG_NOT_SELECTABLE);
 
                             // Despawn Millhouse and all trash
                             instance->SetData(DATA_MILLHOUSE_EVENT_DESPAWN, 0);
diff --git a/src/server/scripts/Maelstrom/Stonecore/boss_slabhide.cpp b/src/server/scripts/Maelstrom/Stonecore/boss_slabhide.cpp
index 345e548e7d5..1a66b356012 100644
--- a/src/server/scripts/Maelstrom/Stonecore/boss_slabhide.cpp
+++ b/src/server/scripts/Maelstrom/Stonecore/boss_slabhide.cpp
@@ -129,6 +129,9 @@ class boss_slabhide : public CreatureScript
 
             void Reset() override
             {
+                if (instance->GetData(DATA_SLABHIDE_INTRO) != DONE)
+                    me->SetFlag(UNIT_FIELD_FLAGS, UNIT_FLAG_NOT_SELECTABLE);
+
                 if (instance->GetData(DATA_SLABHIDE_INTRO) == NOT_STARTED)
                     return;
 
@@ -136,6 +139,7 @@ class boss_slabhide : public CreatureScript
                 me->SetCanFly(false);
                 me->SetDisableGravity(false);
                 me->RemoveByteFlag(UNIT_FIELD_BYTES_1, 3, UNIT_BYTE1_FLAG_ALWAYS_STAND | UNIT_BYTE1_FLAG_HOVER);
+
                 _isFlying = false;
             }
 
@@ -164,6 +168,7 @@ class boss_slabhide : public CreatureScript
                 DespawnAll();
                 summons.DespawnAll();
                 _DespawnAtEvade();
+                me->SetPosition(SlabhideIntroLandPos);
             }
 
             void JustDied(Unit* /*killer*/) override