diff --git a/src/server/scripts/Outland/CoilfangReservoir/SerpentShrine/boss_leotheras_the_blind.cpp b/src/server/scripts/Outland/CoilfangReservoir/SerpentShrine/boss_leotheras_the_blind.cpp
index 79bd3180d..1c14da53f 100644
--- a/src/server/scripts/Outland/CoilfangReservoir/SerpentShrine/boss_leotheras_the_blind.cpp
+++ b/src/server/scripts/Outland/CoilfangReservoir/SerpentShrine/boss_leotheras_the_blind.cpp
@@ -19,6 +19,7 @@
 #include "ScriptMgr.h"
 #include "ScriptedCreature.h"
 #include "serpent_shrine.h"
+#include "TaskScheduler.h"
 
 enum Talk
 {
@@ -59,18 +60,12 @@ enum Misc
 
     NPC_GREYHEART_SPELLBINDER           = 21806,
     NPC_SHADOW_OF_LEOTHERAS             = 21875,
+};
 
-    EVENT_SPELL_BERSERK                 = 1,
-    EVENT_HEALTH_CHECK                  = 2,
-    EVENT_SWITCH_TO_DEMON               = 3,
-    EVENT_SPELL_WHIRLWIND               = 4,
-    EVENT_KILL_TALK                     = 5,
-    EVENT_SWITCH_TO_ELF                 = 6,
-    EVENT_SPELL_INSIDIOUS_WHISPER       = 7,
-    EVENT_SUMMON_DEMON                  = 8,
-    EVENT_RESTORE_FIGHT                 = 9,
-
-    EVENT_SPELL_SHADOW_BOLT             = 20
+enum Groups
+{
+    GROUP_COMBAT                        = 1,
+    GROUP_DEMON                         = 2
 };
 
 const Position channelersPos[MAX_CHANNELERS] =
@@ -80,267 +75,231 @@ const Position channelersPos[MAX_CHANNELERS] =
     {362.11f, -437.48f, 29.52f, 0.9f}
 };
 
-class boss_leotheras_the_blind : public CreatureScript
+struct boss_leotheras_the_blind : public BossAI
 {
-public:
-    boss_leotheras_the_blind() : CreatureScript("boss_leotheras_the_blind") { }
-
-    CreatureAI* GetAI(Creature* creature) const override
+    boss_leotheras_the_blind(Creature* creature) : BossAI(creature, DATA_LEOTHERAS_THE_BLIND)
     {
-        return GetSerpentShrineAI<boss_leotheras_the_blindAI>(creature);
+        scheduler.SetValidator([this]
+        {
+            return !me->HasUnitState(UNIT_STATE_CASTING);
+        });
     }
 
-    struct boss_leotheras_the_blindAI : public BossAI
+    void Reset() override
     {
-        boss_leotheras_the_blindAI(Creature* creature) : BossAI(creature, DATA_LEOTHERAS_THE_BLIND)
-        {
-        }
+        BossAI::Reset();
+        DoCastSelf(SPELL_CLEAR_CONSUMING_MADNESS, true);
+        DoCastSelf(SPELL_DUAL_WIELD, true);
+        me->SetStandState(UNIT_STAND_STATE_KNEEL);
+        me->LoadEquipment(0, true);
+        me->SetReactState(REACT_PASSIVE);
+        _recentlySpoken = false;
+        SummonChannelers();
+
+        ScheduleHealthCheckEvent(15, [&]{
+            if (me->GetDisplayId() != me->GetNativeDisplayId())
+            {
+                //is currently in metamorphosis
+                DoResetThreatList();
+                me->LoadEquipment();
+                me->RemoveAurasDueToSpell(SPELL_METAMORPHOSIS);
+
+                scheduler.RescheduleGroup(GROUP_COMBAT, 10s);
+            }
+            scheduler.CancelGroup(GROUP_DEMON);
+            scheduler.DelayAll(10s);
 
-        void Reset() override
-        {
-            BossAI::Reset();
-            me->CastSpell(me, SPELL_CLEAR_CONSUMING_MADNESS, true);
-            me->CastSpell(me, SPELL_DUAL_WIELD, true);
             me->SetStandState(UNIT_STAND_STATE_KNEEL);
-            me->LoadEquipment(0, true);
             me->SetReactState(REACT_PASSIVE);
-        }
+            me->GetMotionMaster()->Clear();
+            me->StopMoving();
+            Talk(SAY_FINAL_FORM);
 
-        void InitializeAI() override
-        {
-            BossAI::InitializeAI();
-            SummonChannelers();
-        }
-
-        void JustReachedHome() override
-        {
-            BossAI::JustReachedHome();
-            SummonChannelers();
-        }
-
-        void SummonChannelers()
-        {
-            me->ApplySpellImmune(0, IMMUNITY_MECHANIC, MECHANIC_BANISH, false);
-            me->CastSpell(me, SPELL_BANISH, true);
-            me->ApplySpellImmune(0, IMMUNITY_MECHANIC, MECHANIC_BANISH, true);
-
-            summons.DespawnAll();
-            for (uint8 i = 0; i < MAX_CHANNELERS; ++i)
-                me->SummonCreature(NPC_GREYHEART_SPELLBINDER, channelersPos[i], TEMPSUMMON_CORPSE_TIMED_DESPAWN, 5000);
-        }
-
-        void MoveInLineOfSight(Unit*  /*who*/) override { }
-
-        void JustSummoned(Creature* summon) override
-        {
-            summons.Summon(summon);
-        }
-
-        void SummonedCreatureDies(Creature* summon, Unit*) override
-        {
-            me->SetInCombatWithZone();
-            summons.Despawn(summon);
-            if (summon->GetEntry() == NPC_GREYHEART_SPELLBINDER)
-                if (!summons.HasEntry(NPC_GREYHEART_SPELLBINDER))
-                {
-                    me->RemoveAllAuras();
-                    me->LoadEquipment();
-                    me->SetReactState(REACT_AGGRESSIVE);
-                    me->SetStandState(UNIT_STAND_STATE_STAND);
-                    Talk(SAY_AGGRO);
-
-                    events.ScheduleEvent(EVENT_SPELL_BERSERK, 600000);
-                    events.ScheduleEvent(EVENT_HEALTH_CHECK, 1000);
-                    events.ScheduleEvent(EVENT_SWITCH_TO_DEMON, 55000);
-                    events.ScheduleEvent(EVENT_SPELL_WHIRLWIND, 10000);
-                }
-        }
-
-        void KilledUnit(Unit*  /*victim*/) override
-        {
-            if (events.GetNextEventTime(EVENT_KILL_TALK) == 0)
+            scheduler.Schedule(4s, [this](TaskContext)
             {
-                Talk(me->GetDisplayId() != me->GetNativeDisplayId() ? SAY_DEMON_SLAY : SAY_NIGHTELF_SLAY);
-                events.ScheduleEvent(EVENT_KILL_TALK, 6000);
-            }
-        }
-
-        void JustDied(Unit* killer) override
-        {
-            me->CastSpell(me, SPELL_CLEAR_CONSUMING_MADNESS, true);
-            Talk(SAY_DEATH);
-            BossAI::JustDied(killer);
-        }
-
-        void JustEngagedWith(Unit* who) override
-        {
-            BossAI::JustEngagedWith(who);
-            me->SetStandState(UNIT_STAND_STATE_KNEEL);
-        }
-
-        void AttackStart(Unit* who) override
-        {
-            if (who && me->Attack(who, true))
-                me->GetMotionMaster()->MoveChase(who, me->GetDisplayId() == me->GetNativeDisplayId() ? 0.0f : 25.0f);
-        }
-
-        void UpdateAI(uint32 diff) override
-        {
-            if (!UpdateVictim())
-                return;
-
-            events.Update(diff);
-            if (me->HasUnitState(UNIT_STATE_CASTING))
-                return;
-
-            switch (events.ExecuteEvent())
+                DoCastSelf(SPELL_SUMMON_SHADOW_OF_LEOTHERAS);
+            }).Schedule(6s, [this](TaskContext)
             {
-                case EVENT_SPELL_BERSERK:
-                    me->CastSpell(me, SPELL_BERSERK, true);
-                    break;
-                case EVENT_HEALTH_CHECK:
-                    if (me->HealthBelowPct(15))
-                    {
-                        if (me->GetDisplayId() != me->GetNativeDisplayId())
-                        {
-                            DoResetThreatList();
-                            me->LoadEquipment();
-                            me->RemoveAurasDueToSpell(SPELL_METAMORPHOSIS);
-                            events.ScheduleEvent(EVENT_SPELL_WHIRLWIND, 10000);
-                        }
-                        events.CancelEvent(EVENT_SWITCH_TO_DEMON);
-                        events.CancelEvent(EVENT_SPELL_INSIDIOUS_WHISPER);
-                        events.DelayEvents(10000);
-                        events.ScheduleEvent(EVENT_SUMMON_DEMON, 4000);
-                        events.ScheduleEvent(EVENT_RESTORE_FIGHT, 6000);
-                        me->SetStandState(UNIT_STAND_STATE_KNEEL);
-                        me->SetReactState(REACT_PASSIVE);
-                        me->GetMotionMaster()->Clear();
-                        me->StopMoving();
-                        Talk(SAY_FINAL_FORM);
-                        break;
-                    }
-                    events.ScheduleEvent(EVENT_HEALTH_CHECK, 1000);
-                    break;
-                case EVENT_SWITCH_TO_DEMON:
-                    DoResetThreatList();
-                    Talk(SAY_SWITCH_TO_DEMON);
-                    me->LoadEquipment(0, true);
-                    me->GetMotionMaster()->MoveChase(me->GetVictim(), 25.0f);
-                    me->CastSpell(me, SPELL_METAMORPHOSIS, true);
-
-                    events.CancelEvent(EVENT_SPELL_WHIRLWIND);
-                    events.ScheduleEvent(EVENT_SPELL_INSIDIOUS_WHISPER, 25000);
-                    events.ScheduleEvent(EVENT_SWITCH_TO_ELF, 60000);
-                    break;
-                case EVENT_SWITCH_TO_ELF:
-                    DoResetThreatList();
-                    me->LoadEquipment();
-                    me->GetMotionMaster()->MoveChase(me->GetVictim(), 0.0f);
-                    me->RemoveAurasDueToSpell(SPELL_METAMORPHOSIS);
-                    events.ScheduleEvent(EVENT_SWITCH_TO_DEMON, 55000);
-                    events.ScheduleEvent(EVENT_SPELL_WHIRLWIND, 10000);
-                    break;
-                case EVENT_SPELL_WHIRLWIND:
-                    me->CastSpell(me, SPELL_WHIRLWIND, false);
-                    events.ScheduleEvent(EVENT_SPELL_WHIRLWIND, 27000);
-                    break;
-                case EVENT_SPELL_INSIDIOUS_WHISPER:
-                    Talk(SAY_INNER_DEMONS);
-                    me->CastCustomSpell(SPELL_INSIDIOUS_WHISPER, SPELLVALUE_MAX_TARGETS, 5, me, false);
-                    break;
-                case EVENT_SUMMON_DEMON:
-                    me->CastSpell(me, SPELL_SUMMON_SHADOW_OF_LEOTHERAS, true);
-                    break;
-                case EVENT_RESTORE_FIGHT:
-                    me->SetStandState(UNIT_STAND_STATE_STAND);
-                    me->SetReactState(REACT_AGGRESSIVE);
-                    me->GetMotionMaster()->MoveChase(me->GetVictim());
-                    break;
-            }
-
-            if (me->GetDisplayId() == me->GetNativeDisplayId())
-                DoMeleeAttackIfReady();
-            else if (me->isAttackReady(BASE_ATTACK))
-            {
-                me->CastSpell(me->GetVictim(), SPELL_CHAOS_BLAST, false);
-                me->setAttackTimer(BASE_ATTACK, 2000);
-            }
-        }
-    };
-};
-
-class npc_inner_demon : public CreatureScript
-{
-public:
-    npc_inner_demon() : CreatureScript("npc_inner_demon") { }
-
-    CreatureAI* GetAI(Creature* creature) const override
-    {
-        return GetSerpentShrineAI<npc_inner_demonAI>(creature);
+                me->SetStandState(UNIT_STAND_STATE_STAND);
+                me->SetReactState(REACT_AGGRESSIVE);
+                me->GetMotionMaster()->MoveChase(me->GetVictim());
+            });
+        });
     }
 
-    struct npc_inner_demonAI : public ScriptedAI
+    void SummonChannelers()
     {
-        npc_inner_demonAI(Creature* creature) : ScriptedAI(creature)
+        me->ApplySpellImmune(0, IMMUNITY_MECHANIC, MECHANIC_BANISH, false);
+        DoCastSelf(SPELL_BANISH);
+        me->ApplySpellImmune(0, IMMUNITY_MECHANIC, MECHANIC_BANISH, true);
+
+        //probably needs a spell instead
+        summons.DespawnAll();
+        for (uint8 i = 0; i < MAX_CHANNELERS; ++i)
         {
+            me->SummonCreature(NPC_GREYHEART_SPELLBINDER, channelersPos[i], TEMPSUMMON_CORPSE_TIMED_DESPAWN, 5000);
         }
+    }
 
-        ObjectGuid ownerGUID;
-        EventMap events;
+    void JustSummoned(Creature* summon) override
+    {
+        summons.Summon(summon);
+    }
 
-        void EnterEvadeMode(EvadeReason /*why*/) override
+    void SummonedCreatureDies(Creature* summon, Unit*) override
+    {
+        me->SetInCombatWithZone();
+        summons.Despawn(summon);
+        if (summon->GetEntry() == NPC_GREYHEART_SPELLBINDER)
         {
-            me->DespawnOrUnsummon(1);
-        }
-
-        void IsSummonedBy(WorldObject* summoner) override
-        {
-            if (!summoner)
-                return;
-
-            ownerGUID = summoner->GetGUID();
-            events.Reset();
-            events.ScheduleEvent(EVENT_SPELL_SHADOW_BOLT, 4000);
-        }
-
-        void JustDied(Unit* /*killer*/) override
-        {
-            if (Unit* unit = ObjectAccessor::GetUnit(*me, ownerGUID))
-                unit->RemoveAurasDueToSpell(SPELL_INSIDIOUS_WHISPER);
-        }
-
-        void DamageTaken(Unit* who, uint32& damage, DamageEffectType, SpellSchoolMask) override
-        {
-            if (!who || who->GetGUID() != ownerGUID)
-                damage = 0;
-        }
-
-        bool CanAIAttack(Unit const* who) const override
-        {
-            return who->GetGUID() == ownerGUID;
-        }
-
-        void UpdateAI(uint32 diff) override
-        {
-            if (!UpdateVictim())
-                return;
-
-            events.Update(diff);
-            if (me->HasUnitState(UNIT_STATE_CASTING))
-                return;
-
-            switch (events.ExecuteEvent())
+            if (!summons.HasEntry(NPC_GREYHEART_SPELLBINDER))
             {
-                case EVENT_SPELL_SHADOW_BOLT:
-                    me->CastSpell(me->GetVictim(), SPELL_SHADOW_BOLT, false);
-                    events.ScheduleEvent(EVENT_SPELL_SHADOW_BOLT, 6000);
-                    break;
-            }
+                me->RemoveAllAuras();
+                me->LoadEquipment();
+                me->SetReactState(REACT_AGGRESSIVE);
+                me->SetStandState(UNIT_STAND_STATE_STAND);
+                Talk(SAY_AGGRO);
 
+                scheduler.Schedule(10min, [this](TaskContext)
+                {
+                    DoCastSelf(SPELL_BERSERK);
+                });
+
+                ElfTime();
+            }
+        }
+    }
+
+    void ElfTime()
+    {
+        scheduler.Schedule(25050ms, 32550ms, GROUP_COMBAT, [this](TaskContext context)
+        {
+            DoCastSelf(SPELL_WHIRLWIND);
+            context.Repeat(30250ms, 34900ms);
+        }).Schedule(60350ms, GROUP_DEMON, [this](TaskContext)
+        {
+            DoResetThreatList();
+            Talk(SAY_SWITCH_TO_DEMON);
+            DemonTime();
+        });
+    }
+
+    void DemonTime()
+    {
+        me->LoadEquipment(0, true);
+        me->GetMotionMaster()->MoveChase(me->GetVictim(), 25.0f);
+        DoCastSelf(SPELL_METAMORPHOSIS, true);
+
+        scheduler.CancelGroup(GROUP_COMBAT);
+        scheduler.Schedule(24250ms, GROUP_DEMON, [this](TaskContext)
+        {
+            Talk(SAY_INNER_DEMONS);
+            me->CastCustomSpell(SPELL_INSIDIOUS_WHISPER, SPELLVALUE_MAX_TARGETS, 5, me, false);
+        }).Schedule(60s, [this](TaskContext)
+        {
+            DoResetThreatList();
+            me->LoadEquipment();
+            me->GetMotionMaster()->MoveChase(me->GetVictim(), 0.0f);
+            me->RemoveAurasDueToSpell(SPELL_METAMORPHOSIS);
+            ElfTime();
+        });
+    }
+
+    void UpdateAI(uint32 diff) override
+    {
+        if (!UpdateVictim())
+            return;
+
+        scheduler.Update(diff);
+        if (me->HasUnitState(UNIT_STATE_CASTING))
+            return;
+
+        if (me->GetDisplayId() == me->GetNativeDisplayId())
+        {
             DoMeleeAttackIfReady();
         }
-    };
+        else if (me->isAttackReady(BASE_ATTACK))
+        {
+            me->CastSpell(me->GetVictim(), SPELL_CHAOS_BLAST, false);
+            me->setAttackTimer(BASE_ATTACK, 2000);
+        }
+    }
+private:
+    bool _recentlySpoken;
+};
+
+struct npc_inner_demon : public ScriptedAI
+{
+    npc_inner_demon(Creature* creature) : ScriptedAI(creature)
+    {
+        _scheduler.SetValidator([this]
+        {
+            return !me->HasUnitState(UNIT_STATE_CASTING);
+        });
+
+        _instance = creature->GetInstanceScript();
+    }
+
+    void EnterEvadeMode(EvadeReason /*why*/) override
+    {
+        me->DespawnOrUnsummon(1);
+    }
+
+    void IsSummonedBy(WorldObject* summoner) override
+    {
+        if (!summoner)
+            return;
+
+        _scheduler.CancelAll();
+        _scheduler.Schedule(4s, [this](TaskContext context)
+        {
+            DoCastVictim(SPELL_SHADOW_BOLT);
+            context.Repeat(6s);
+        });
+    }
+
+    void JustDied(Unit* /*killer*/) override
+    {
+        if (Creature* leotheras = _instance->GetCreature(DATA_LEOTHERAS_THE_BLIND))
+        {
+            leotheras->RemoveAurasDueToSpell(SPELL_INSIDIOUS_WHISPER);
+        }
+    }
+
+    void DamageTaken(Unit* who, uint32& damage, DamageEffectType, SpellSchoolMask) override
+    {
+        if (Creature* leotheras = _instance->GetCreature(DATA_LEOTHERAS_THE_BLIND))
+        {
+            if (!who || who->GetGUID() != leotheras->GetGUID())
+            {
+                damage = 0;
+            }
+        }
+    }
+
+    bool CanAIAttack(Unit const* who) const override
+    {
+        if (Creature* leotheras = _instance->GetCreature(DATA_LEOTHERAS_THE_BLIND))
+        {
+            return who->GetGUID() == leotheras->GetGUID();
+        }
+        return false;
+    }
+
+    void UpdateAI(uint32 diff) override
+    {
+        if (!UpdateVictim())
+        {
+            return;
+        }
+
+        _scheduler.Update(diff);
+
+        DoMeleeAttackIfReady();
+    }
+private:
+    TaskScheduler _scheduler;
+    InstanceScript* _instance;
 };
 
 class spell_leotheras_whirlwind : public SpellScriptLoader
@@ -516,8 +475,8 @@ public:
 
 void AddSC_boss_leotheras_the_blind()
 {
-    new boss_leotheras_the_blind();
-    new npc_inner_demon();
+    RegisterSerpentShrineAI(boss_leotheras_the_blind);
+    RegisterSerpentShrineAI(npc_inner_demon);
     new spell_leotheras_whirlwind();
     new spell_leotheras_chaos_blast();
     new spell_leotheras_insidious_whisper();