diff --git a/src/server/scripts/Kalimdor/CavernsOfTime/TheBlackMorass/instance_the_black_morass.cpp b/src/server/scripts/Kalimdor/CavernsOfTime/TheBlackMorass/instance_the_black_morass.cpp
index ae1e22d75..3221506c9 100644
--- a/src/server/scripts/Kalimdor/CavernsOfTime/TheBlackMorass/instance_the_black_morass.cpp
+++ b/src/server/scripts/Kalimdor/CavernsOfTime/TheBlackMorass/instance_the_black_morass.cpp
@@ -48,8 +48,8 @@ public:
         GuidSet encounterNPCs;
         uint32 encounters[MAX_ENCOUNTER];
         ObjectGuid _medivhGUID;
-        uint8  _currentRift;
-        uint8  _shieldPercent;
+        uint8 _currentRift;
+        int8 _shieldPercent;
 
         void Initialize() override
         {
@@ -144,7 +144,7 @@ public:
             }
         }
 
-        void SetData(uint32 type, uint32  /*data*/) override
+        void SetData(uint32 type, uint32 data) override
         {
             switch (type)
             {
@@ -187,10 +187,19 @@ public:
                     Events.RescheduleEvent(EVENT_NEXT_PORTAL, 3000);
                     break;
                 case DATA_DAMAGE_SHIELD:
-                    --_shieldPercent;
+                {
+                    _shieldPercent -= data;
+                    if (_shieldPercent < 0)
+                    {
+                        _shieldPercent = 0;
+                    }
+
                     DoUpdateWorldState(WORLD_STATE_BM_SHIELD, _shieldPercent);
+
                     if (!_shieldPercent)
+                    {
                         if (Creature* medivh = instance->GetCreature(_medivhGUID))
+                        {
                             if (medivh->IsAlive())
                             {
                                 Unit::Kill(medivh, medivh);
@@ -198,10 +207,17 @@ public:
                                 // Xinef: delete all spawns
                                 GuidSet eCopy = encounterNPCs;
                                 for (ObjectGuid const& guid : eCopy)
+                                {
                                     if (Creature* creature = instance->GetCreature(guid))
+                                    {
                                         creature->DespawnOrUnsummon();
+                                    }
+                                }
                             }
+                        }
+                    }
                     break;
+                }
             }
         }
 
diff --git a/src/server/scripts/Kalimdor/CavernsOfTime/TheBlackMorass/the_black_morass.cpp b/src/server/scripts/Kalimdor/CavernsOfTime/TheBlackMorass/the_black_morass.cpp
index 0fec969f0..b1d88ca83 100644
--- a/src/server/scripts/Kalimdor/CavernsOfTime/TheBlackMorass/the_black_morass.cpp
+++ b/src/server/scripts/Kalimdor/CavernsOfTime/TheBlackMorass/the_black_morass.cpp
@@ -387,16 +387,32 @@ public:
     {
         PrepareAuraScript(spell_black_morass_corrupt_medivh_AuraScript);
 
+        bool Load() override
+        {
+            _ticks = 0;
+            return true;
+        }
+
         void PeriodicTick(AuraEffect const* /*aurEff*/)
         {
-            if (InstanceScript* instance = GetUnitOwner()->GetInstanceScript())
-                instance->SetData(DATA_DAMAGE_SHIELD, 1);
+            if (++_ticks >= 3)
+            {
+                _ticks = 0;
+
+                if (InstanceScript* instance = GetUnitOwner()->GetInstanceScript())
+                {
+                    instance->SetData(DATA_DAMAGE_SHIELD, m_scriptSpellId == SPELL_CORRUPT_AEONUS ? 2 : 1);
+                }
+            }
         }
 
         void Register() override
         {
             OnEffectPeriodic += AuraEffectPeriodicFn(spell_black_morass_corrupt_medivh_AuraScript::PeriodicTick, EFFECT_0, SPELL_AURA_PERIODIC_TRIGGER_SPELL);
         }
+
+    private:
+        uint8 _ticks = 0;
     };
 
     AuraScript* GetAuraScript() const override