Hellfire High Council Encounter Mechanics

The three bosses of the Hellfire High Council encounter are Gurtogg Bloodboil, Blademaster Jubei'thos, and Dia Darkwhisper; players will engage all three bosses at once.
  • These bosses do not share health, and should be defeated one at a time
  • The suggested kill order is Gurtogg > Jubei'thos > Dia
  • When a boss reaches 30% health (Final Hour), they gain a new ability that will persist through the fight even after their death
  • It is very important not to push two bosses below 30% health at the same time
  • Players must be careful with multi-DoTting and cleave abilities
  • Once a boss has reached 30% health, players must defeat the boss quickly
Each boss has a handful of abilities they will use continuously, a "Final Hour" ability they gain below 30% health, and a very powerful ability that they take turns using every 1:15 throughout the fight.

Dia Darkwhisper

Dia Darkwhisper is a caster with powerful, shadow-themed abilities.

  • Dia's Void Haze ability means she must be tanked far away from the other two bosses, so that the other bosses do not become immune to damage
  • Bosses under the effect of Dia's Void Haze become shadowy and transparent; if tanks see this, they must move the boss away from Dia
  • Dia will attack her threat target with Void Bolt, which can be interrupted
  • Every 35 seconds, Dia will gain Nightmare Visage, dealing heavy damage to her tank
  • During Nightmare Visage, tanks should use strong survivability cooldowns or call for a healer's external CD
  • If the tank leaves melee range during Nightmare Visage, Dia will Charge to them; she cannot be kited to avoid the Visage damage
However, the most important of Dia Darkwhisper's abilities is the interaction between Mark of the Necromancer and Reap.
  • Dia will cast Mark of the Necromancer on a player about once every 70 seconds
  • This debuffs the player with a Magical DoT that deals increasing damage with each tick
  • As the debuff grows in damage, its icon changes color, allowing healers to quickly assess the severity of a player's debuff
  • The weak version is Mark of the Necromancer; the moderate version is Mark of the Necromancer; the strong version is Mark of the Necromancer
  • When Mark of the Necromancer is dispelled from a player, it jumps to two new targets, resetting its damage

When Dia Darkwhisper casts Reap, which occurs a minute into the fight and every 70 seconds thereafter, as well as immediately upon reaching 30% health, she will remove all active Mark of the Necromancer debuffs, creating small purple Reap zones under the feet of each affected player.

  • Reap deals heavy damage to players standing inside its area of effect, and will stack if more than one Reap puddle spawns in the same location
  • During Reap's long cast time, players afflicted by Mark of the Necromancer must run out of the raid to drop their Reap zones in unused areas of the room
  • Once the Reap cast completes and the puddle forms, players must move out of the puddle quickly to limit their damage intake
  • Note that dispelling a player during the Reap cast will still create a Reap puddle under that player, as well as the two players it jumps to
  • Healers should avoid dispelling Mark of the Necromancer during the Reap cast
Healers must manage Mark of the Necromancer carefully to avoid spreading the debuff to too many players. The debuff should be dispelled when it is in its most powerful, red form, or if it is on a player also targeted by another debuff, or if it is on a tank just before Dia casts Reap.

When Dia reaches 30% health and enters Her Final Hour, she will immediately Reap to remove existing Mark of the Necromancerdebuffs, and will then cast Mark of the Necromancer on half of the raid at once.
  • During this time Dia will no longer cast Reap
  • As a result, as healers begin to dispel dangerously high Mark of the Necromancer debuffs, the entire raid will eventually become covered by Mark of the Necromancerdebuffs
  • Once this happens, healers should just dispel on CD, since this will overwrite high-damage Mark of the Necromancer debuffs with the low-damage versions when it bounces

After Dia dies, Mark of the Necromancer will remain active until all bosses are defeated. This is why Dia should be killed last - her final 30% is very difficult to heal through, and healers will run out of mana quickly if Dia is killed before the other bosses.

Blademaster Jubei'thos and Gurtogg Bloodboil should be tanked together on the opposite side of the room from Dia Darkwhisper.

Blademaster Jubei'thos

Jubei'thos will use two abilities frequently:

  • Felstorm, which he will cast approximately every 30 seconds, deals moderate, unavoidable raid-wide damage
  • Although this ability looks like a whirlwind-type effect, players will take the same amount of damage no matter where they are in the room, so melee do not need to run out
  • Jubei'thos will also throw his Fel Blade in a randomly-chosen direction, dealing heavy damage and knocking back any player in its path
  • The green arrow at Jubei'thos's feet will indicate the direction in which Fel Blade will travel
  • Players, particularly melee DPS, should make sure to move out of the Fel Blade's path

When Jubei'thos reaches 30% health and enters His Final Hour, he will begin to use Wicked Strike, summoning an image of himself behind half of the players in the raid and dealing moderate Fire damage. This ability will occur about once every 8 seconds, and each time it is used, it increases in damage by 5%. After Jubei'thos dies, he will continue to use Wicked Strike on the raid, and it will continue to increase in damage.

Gurtogg Bloodboil

Gurtogg Bloodboil's melee attacks debuff his target with Acidic Wound, which stacks and deals weak to moderate Nature damage every 2 seconds. Because tank-swapping is not feasible in this fight due to Void Haze, the Gurtogg/Jubei'thos tank must take advantage of Bloodboil's Fel Rage ability to clear the stacks.

Gurtogg will cast Fel Rage on a random player once a minute, and fixates on that player for 30 seconds.

  • Fel Rage increases the player's damage dealt, healing done, and Leech rating significantly
  • Gurtogg will run to the Fel Rage target and melee them until Fel Rage fades, and will then return to the tank
  • The player targeted by Fel Rage should kite the boss 25-30 yards away from the tank so that Gurtogg's travel time will allow the tank's Acidic Wounds to drop
  • Do not kite Gurtogg toward Dia! Void Haze completely negates the additional damage from Fel Rage
  • Targeted players should use personal survivability cooldowns and focus on using the DPS boost to damage Gurtogg significantly
  • Healers must pay special attention to keeping the Fel Rage target alive

During the Fel Rage, Gurtogg will also gain stacks of Fury. This buff can be removed by Enrage-dispelling effects such as (Spell #2908) and (Spell #19801), but players should wait until Fel Rage has ended, so they will remove all the stacks with a single cast.

Additionally, Gurtogg will cast Bloodboil frequently, targeting the five furthest-away players and dealing moderate damage. This damage is unavoidable, but not significant enough to require a strategy. Players who are on low health can move closer to Gurtogg to avoid taking Bloodboil damage if necessary.

When Gurtogg reaches 30% health and enters His Final Hour, he will begin to debuff the raid with Tainted Blood, a stacking debuff that lowers players' maximum health by 10% per stack. This is cast once every 15 seconds, and after Gurtogg dies, players will retain their stacks. It is important for players to defeat Gurtogg quickly after he has been pushed to 30% health, to avoid gaining too many stacks; 3 or fewer stacks should be the goal.

Ultimate Abilities

At 1:15 into the fight, and approximately every 1:15 thereafter, one of the existing bosses will use a very powerful, "ultimate" ability:
  • Dia Darkwhisper will summon Wailing Horrors and fills the room with Darkness for 15 seconds
  • Blademaster Jubei'thos will Windwalk, vanishing from combat, but spawning Mirror Images; he will return after 45 seconds or all Mirror Images have died
  • Gurtogg Bloodboil will use Demolishing Leap, jumping to distant locations and dealing damage to the raid based upon their proximity to his landing site
  • These are excellent times for raid cooldowns, as these abilities deal heavy damage for extended periods of time

The order in which these abilities will be used is Dia, then Jubei'thos, then Gurtogg; once one boss dies, they are removed from the rotation, and the remaining two will alternate the use of their powerful ability. While one of these abilities is active, some of the bosses' other abilities are disabled. For example, Jubei'thos will not use Felstorm during Dia's Wailing Horror or Gurtogg's Demolishing Leap.

During Dia's Wailing Horrors ability, players must dodge the Wailing Horrors to avoid taking very heavy damage. These Horrors spawn as ghostly forms along the edges of the room, solidify into dark purple demons, and then rush through the center of the room. Players can simply side-step the Horrors' path to avoid the damage. The raid will also take damage every second from Darkness, which is unavoidable.

During Windwalk, players must quickly kill the eight Mirror Images that Jubei'thos leaves behind. The Mirror Images have health based upon Jubei'thos's health at the time he used Windwalk, so when Jubei'thos is on low health and uses this ability, the Mirror Images will die much more quickly than when Jubei'thos uses it at the beginning of the fight.

The Mirror Images will cast weaker versions of Jubei'thos's Felstorm and Fel Blade abilities. Although each individual use is weaker than Jubei'thos's version, they add up to a lot more damage than Jubei'thos himself inflicted, so raid cooldowns, particularly damage-reduction cooldowns, will be particularly valuable here. It is also important that players dodge the Mirror Images' Fel Bladeattacks.

Jubei'thos will reappear after 45 seconds whether all the Mirror Images are dead or not.

When Gurtogg uses Demolishing Leap, players should use speed boosts to move away from the location that Gurtogg will leap to, in order to minimize damage taken. Because Gurtogg is the first kill target and uses his Demolishing Leap third, nearly four minutes into the fight, it is quite possible that some raids will never see this ability.

Take care not to push a Gurtogg or Jubei'thos below 30% health if their "ultimate" ability will be used soon; this will prolong the raid's exposure to the Final Hour ability and make the fight more difficult.


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