N'Zoth the Corruptor
This is a three phase encounter where you will alternate between inside of N'Zoths mind and outside of it. During each phase you must deal with various adds in order to reach the final phase where you can attack N'Zoth directly.
Throughout the entire fight you will have a Sanity bar, this functions in the same way that it did for the Carapace of N'Zoth encounter where if your Sanity ever reaches 0 you will gain the Gift of N'Zoth buff which will provide you with a 100% increase to your damage and healing done for 20 seconds. However, when this buff expires you will become a Servant of N'Zoth, and repeatedly cast Mental Decay on players in the raid which will reduce their Sanity.
If you move or cast a spell the channel will stop.
Phase 1 (Inside the Mindscape)
As soon as the encounter begins N'Zoth will transport everyone into the Mindscape where you will face against Psychus, and the Exposed Synapse tentacles. N'Zoth will have a shield around himself reducing his damage taken.
These surround the encounter area and will open periodically. When they do open they will cast Void Gaze.
Void Gaze - This ability will deal a small amount of Shadow damage and drain 5% Sanity from all players every second for 3 seconds.
When Psychus has been killed you are able to interact with your body that was created when you entered the Mindscape and Restore Consciousness to return to the Physical Realm.
N'Zoth and all tentacles alive will also be stunned for 30 seconds from Shattered Ego, this stun removes the damage reduction shield temporarily on N'Zoth in the Physical Realm.
Corrupted Neuron - These will spawn all over the room, regenerate 1% health every 2 seconds, and project a Veil of Anguish from their locations, the centre of the room, and the perimeter. The size of the Veil of Anguish around the Corrupted Neuron will reduce as their health is lower. If any players are stood within the Veil of Anguish, they will be affected by Anguish. They will take large amounts of Shadow damage, lose 10 Sanity every 2 seconds and their movement speed will be slowed by 33%.
Whilst you are under the effects of Paranoia all non-partner players will make you lose 5 Sanity every second if you are within 5 yards of them.
Eternal Torment - All players in the Physical Realm will take a light amount of Shadow damage when this is cast.
Mindgate - A portal to the Mindscape will open and half of the raid can enter at a time.
Tumultuous Burst - If no players are in range of the Basher Tentacle it will cast this spell. This will deal a moderate amount of Shadow damage to all players every 2 seconds for 10 seconds, and reduce Haste by 33% for 10 seconds.
Void Lash - This will deal a large amount of Physical damage and a moderate amount of Shadow damage every 0.8 seconds for 6 seconds. You will need to use a defensive/external on this.
Evolving Might - The tentacle will gain a stack of this buff every melee swing they make. This buff will increase their damage by 3%.
Corrupted Mind - This spell can be interrupted. If it is not interrupted it will apply a debuff on the target which will deal a small amount of Shadow damage every 2 seconds for 10 seconds. If this debuff is not dispelled the player will lose 15 Sanity.
This is the lowest priority to kill and for the most part can just be multi-dotted.
Pain Spike - This will deal a light amount of Shadow damage on their target.
This Phase is the same as Phase 1 however either Deathwing or Azshara & Sylvanas will join.
Flames of Insanity - You will take a moderate amount of Fire damage and lose 20 Sanity instantly. You will be burning and take a small amount of Fire damage every 2 seconds for 6 seconds and be disoriented for the duration.
Azshara & Sylvanas
Please note: During my PTR testing this Phase did not trigger.
Black Volley - All players in the Mindscape will take a small amount of Shadow damage and have 5 Sanity drained every second for 3 seconds.
Phase 3 will begin once the whole raid has entered and left the Mindscape.
Phase 3 (N'Zoth)
During this phase you are able to attack N'Zoth directly and he will retain his Mindgrasp and Paranoia abilities. He will also spawn Thought Harvester's throughout the Phase which need to be dealt with as a high priority.
Evoke Anguish - This debuff will be applied to several players and lasts for 8 seconds. The players will take a moderate amount of Shadow damage every 5.2 seconds and when the debuff expires an Anguish puddle will spawn on the floor. This puddle will grow in size after it has spawned and each subsequent cast of Evoke Anguish will make existing Anguish puddles grow in size.
This needs to be managed well else you will run out of space.
Stupefying Glare - Eyes will spawn at N'Zoth based on player locations. After a few seconds they will start to channel void energy for 4 seconds. Any players caught in these will take a moderate amount of Shadow damage and be feared for 4 seconds.
If this ability does not hit at least 5 players, the entire raid will lose 50 Sanity.
Phase 1 from Normal and Heroic has been removed. You will begin the fight in Phase 2.
When an Exposed Synapse is killed a Psychopage add will spawn.
Devour Thoughts - This will deal a large amount of Shadow damage and drain 10 Sanity from all players within 10 yards.
Psychic Burst - When a Psychopage is killed it will deal a large amount of Shadow damage and drain 30 Sanity from all players within 5 yards.
When you kill Psychus you will only stun N'Zoth and not the tentacles around the room.
There is an additional Phase with no details other than Magni and MOTHER joining the battle.
Tank Damage Profile
Phase 1 - You can swap after each cast of Synaptic Shock
Phase 2 - 1 Tank should be in each Mindscape Group
Phase 2 - The tank that is in the Physical Realm needs to ensure they are on each Basher Tentacle when it spawns
Phase 2 - Utilise defensive cooldowns or externals for each Void Lash cast
Phase 3 - Swap on each cast of Mindwrack
Your high mobility is useful in Phase 2 to get to new Tentacle spawn locations to prevent the Basher from being alone
Vengeance Demon Hunter
Infernal Strike is useful in Phase 2 to get to new Tentacle spawn locations to prevent the Basher from being alone
Divine Steed should be used to move around the room to get to new Tentacle spawn locations in Phase 2 to prevent the Basher from being alone
Mindwrack and the Physical portion of Void Lash are blockable
Heroic Leap is useful in Phase 2 to get to new Tentacle spawn locations to prevent the Basher from being alone
Stampeding Roar can be very helpful with moving around the room in Phase 2
Blood Death Knight
Wraith Walk should be talented and used to move around the room to get to new Tentacle spawn locations in Phase 2 to prevent the Basher from being alone