Tanking: 3 tanks (2 on 10-man). Phase 1 requires no main tanking, only add tanking. In Phase 2 tanks will need to swap at around 3 stacks of Touch of Insignificance (swapping at 2 will be too soon and your debuffs won’t have faded).

Healing: This fight isn’t especially healing-intensive.

• Phase 1: There will be random spike damage from shadow bolts and clustered damage from the D&D. Tanks will also be taking moderate damage. It is worth assigning healers to sides to ensure that tanks and melee are covered, since the room is pretty big.
• Phase 2: Tank damage can be fairly spiky if Frostbolts get through, but is fairly gentle otherwise. Vengeful Shades can cause significant damage, especially in combination with D&D, so keeping the raid topped off, especially slow-moving raiders, is important. Spread healers out, to avoid having too many moving at once.

Buffs: At least one Decurse is very useful. Frost and Shadow Resistance could help, but are not game-breaking.

Key Debuffs: Touch of Insignificance (Undispellable), Curse of Torpor (Curse), Dominate Mind (Undispellable, 25-man or heroic only), Necrotic Strike (Undispellable). Vampiric Might should be spellstolen from the Cult Fanatics.

HP: 3 million (13.4 million on 25-man), plus a mana shield of the same value.

Phase 1

During Phase 1 Lady Deathwhisper will have a mana shield that will absorb all the damage done to her. She will attack the raid with a green Death and Decay (run away, little girl!), Shadow Bolts, and a single Dominate Mind evry 40 seconds or so on 25-man normal and both heroic modes. Those getting MC’d should be CC’d quickly.

During this phase (after 5 seconds of combat and every 60 seconds thereafter) adds will come in waves from the sides of the room – 3 Cult Adherents and 3 Cult Fanatics in total per wave, plus one random type from the stairs. On 10-man there will be a single group of 3 which will spawn from alternating sides. Where these are tanked is not too important in normal mode, but since for heroic you will want to tank them under Lady Deathwhisper it is worth getting used to this on normal mode as well. Ideally Deathwhisper is moved to the stairs through the use of copious interrupts, although letting the adds come to her also works.

Cult Fanatics cleave, so mêlée should mind their position. They also put a debuff (Necrotic Strike) on their tank which absorbs 9k (18k on 25-man) healing, and cast Vampiric Might on themselves, which causes them to heal for 300% of the damage they do and to do 25% more damage. This is dispellable and, crucially, spellstealable.
Cult Adherents will cast Curse of Torpor on random raid members which increases the cooldown of any ability used while the debuff is active by 15s, so this needs to be removed PDQ.

Not content with just a simple adds fight though, Blizzard added a few ways in which to raise the complexity of the encounter.

First, Deathwhisper will cause one of her Adherents to cast Dark Empowerment on themselves (2.5s, not interruptable), making them immune to interrupts and increasing their potency. Empowered Adherents will cast Deathchill Blast, dealing around 10k damage to enemies within 10 yards, and will cast Shroud of the Occult, deflecting spells back to their caster.

Second, every 30 seconds one of the Fanatics will cast Dark Transformation (2.5s, not interruptable), which will transform it into a Deformed Fanatic and increase its damage by 100% and its size by 50%. This can easily take out a tank and should be kited until it can be nuked immediately. It moves fairly slowly, and can be kited by just about anyone.

Finally, every 30 seconds one of the adds alive at the time will begin to cast Dark Martyrdom. When this 4 second non-interruptible cast completes the add will explode for 12,000 Shadowstorm damage in a 10-yard radius and change into either a Reanimated Fanatic or Reanimated Adherent (as appropriate), heal to full, and will become immune to either physical or magical damage respectively. Therefore:

• Mêlée/hunters should attack Reanimated Adherents.
• Casters should attack Reanimated Fanatics.

However, if DPS switch to kill the Reanimated adds there is a possibility that a second add will reanimate. Therefore DPS should finish killing off the normal adds before dealing with the Reanimated ones.

Overall DPS kill priority is:

Deformed Fanatic > Empowered Adherent > Cult Adherent/Fanatic > Reanimated Adherent/Fanatic (physical DPS on Adherents, casters on Fanatics)

Phase 2

Phase 2 begins when Lady Deathwhisper’s mana barrier has been drained. She resets aggro and a tank needs to pick her up quickly before the DPS take aggro.

Her primary attack is interruptable (but not resistable) 48k Frostbolts (like Kel’Thuzad) so melee should be assigned to interrupt these where possible (more important on heroic). She also does a Frostbolt Volley, which can hinder people’s escape from Vengeful Shades but does not hurt too badly (around 10k Frost damage).

She will no longer summon Cultists, but Vengeful Shades will spawn in this phase and pick a random player to chase, dealing 11-18k shadowfrost damage to them should they catch them. They cannot be DPS’d so people need to run away from them until they die naturally.

She will stack Touch of Insignificance on her current tank approximately every 8 seconds, reducing their threat generation by 20% for 30s. Tanks should swap at 3-4 stacks, whenever they are free of the debuff, in order to keep the threat output fairly high. DPS need to be aware of the variable TPS tanks will be generating, and throttle back accordingly.

Heroic

• Deathwhisper has double the health and mana that she has on normal.
• Deathwhisper’s Frostbolts and Frostbolt Volley hit a lot harder. Frostbolts really need to be always interrupted, and Volley as well if there are sufficient interrupts.
• All adds also have more health and their abilities deal significantly more damage.
• Deathwhisper casts Dominate Mind on one person at a time in 10-man heroic and on 3 people at a time on 25-man heroic.
• Adds spawn every 45s in Phase 2. One from the back in 10-man and one side at a time in 25-man.
• The Phase 2 Vengeful Shades are likely to almost one-shot players, especially on 25-man, so you must run away from them. The Vengeful Blast they cast is now 10-yard AoE, so the Shades must be kited out of the raid, especially by melee.
• Deathwhisper is not tauntable in phase 2, so both tanks will need to be highest on threat at all times.

The main differences that affects the fight is the need to deal more efficient damage to the adds and to Deathwhisper, so the adds should be tanked under Deathwhisper so that AoE and cleaves can damage her as well as the adds, and so that melee can kill any Reanimated Adherents and ranged can kill Reanimated Fanatics quickly, although ideally no adds will live long enough to Reanimate.

The raid should be positioned behind the boss so that adds will run past the tanks on their way in and aid in the pickup.

Achievement – Full House

The goal of this achievement is to kill Deathwhisper with all five types of add alive when she dies. The difficulty is twofold: the adds themselves will be dealing damage and causing trouble, and need to be controlled well, but also there is a need for careful timing so that you are able to keep the right adds alive.

When the first set of adds spawns, they should be picked up by the tanks while the DPS remain on the boss. The tanks should simply wait until the adds have transformed, and should mark the ones which will be retained. The goal of this phase is to get:

• Deformed Fanatic
• Reanimated Fanatic
• Reanimated Adherent

Note that the Empowered Adherent does not appear to count as a separate mob type for this achievement.

The Reanimated Fanatic can be controlled using Shackle Undead, Turn Evil or other CC; the Deformed Fanatic needs to be kited.

Once you have these, kill off any regular Fanatics/Adherents which are not needed any more and take Deathwhisper’s mana shield down to about 5%.

The key to this fight is timing the transition correctly. You want to have a new wave spawn, and then immediately take down the mana shield. Once Deathwhisper is in Phase 2 she will not cause any further transformations. From this point on it is a straight nuke to kill her before the second tank is needed or the adds get too much to handle, so this would be a good time to blow Bloodlust. The second tank can help, but this might add extra strain on healing. Also try polymorphing any adds that aren’t in danger of being insta-cleaved, to lower the incoming damage.