Overview
Stay near Zul'jan. Incoming damage is high enough that a spread raid just dies to Fangs of the Coiled Altar. Collect Coalesced Venom to a dump pad, then have the tank erase the pile with Sever. Venom Rupture is a stacking DoT, so do not detonate the whole dump at once unless healers called it. Ritual of the Fang is the 4-second channel from the altar itself. Intercept those beams or he drinks them. Leftover orbs explode when he dies, so do not transition on a fresh Toxic Deluge.
Malacrass uses the same stacked raid, but now you break Dreadmarch shields, face Manifestation of Dread adds, and cut them down with Soul Sever. They only walk when you look away. Eternal Nightfall only interrupts after Veil of Twilight is broken. Bloodlust the Soulbinding intermission, when Zul'jan takes double damage, then finish both together in Phase 3.
Phase 1
Toxic Deluge drops green circles that become Coalesced Venom. Assigned runners pick them up, park on the dump pad, and drop when Volatile Venom expires. Each pop is Venom Rupture, a stacking DoT, so do not detonate the whole dump at once unless healers called it. Sever is a tank frontal that also destroys orbs in the cone and applies a taken-increase. Aim it through the dump, then taunt-swap. Guillotine needs two half-raid groups because Guillotined is 500% taken. Widow's Kiss is the follow-up circle: soak, then leave. Dispel Venomfang. Watch Axegrinder lanes while you do all of that.
Phase 2
Stack slightly off-center behind him. Dreadmarch mind-controls players toward the nearest edge under an absorb. Breaking it spawns Manifestation of Dread adds. Grips and knockbacks help hold those players. Fixated players steer their add to the dump, then stare at it to freeze it. Manifestations reapply Dreadmarch if they reach you. Soul Sever is Sever plus three Soul Fragments the tank must reclaim or they die. Gloombomb ranged circles explode and apply Gravebound. Run out, then collect fragments.
Spiritcackle adds a Wail of Terror caster that teleports when interrupted. Ranged should kill it before it walks into melee. When the veil goes up, swap to shield damage, then interrupt Eternal Nightfall as late as you safely can. A Nightfall with the veil still up is a wipe. Clear remaining Manifestations before he dies so they do not knock people off in the transition.
Intermission
Malacrass links to Zul'jan. Ghastly Regeneration heals Zul'jan while he takes 100% more damage. Lust, potions, everything. Fragments of Malacrass walk in and Reclaim Essence if they land. Intercepting one is Spirit Erasure (raid-wide). Stagger soaks. If the raid is too low, skip a fragment and eat the heal rather than a chain-wipe.
Phase 3
Both kits run at once. They do not share health. Balance their bars and kill them in the same window. The survivor enrages. Stack them for cleave. The new failure is a Guillotine and a Dreadmarch landing in the same space.
By role
Tanks
Face both bosses away. Intercept Ritual of the Fang. Aim Sever and Soul Sever through orbs and Manifestations, then swap. Collect Soul Fragments immediately.
Healers
Ramp Fangs of the Coiled Altar, staggered Venom Rupture pops, split Guillotine groups, and Eternal Nightfall. Break Dreadmarch shields before those players walk off. Stagger Spirit Erasure soaks.
DPS
Collect venom to the dump and pop it in waves. Dodge Axegrinder. Herd Manifestations into Soul Sever. Kill the Spiritcackle caster at range. Break Veil of Twilight, interrupt Eternal Nightfall, soak Fragments, and kill both bosses together before Soulbinding completes.
Why pulls die
Phase 1 deaths are Sever on the raid, Axegrinder lanes, a whole dump detonating Venom Rupture at once, overlapping Guillotined soaks, and leftover orbs exploding on the transition. Phase 2 wipes are Dreadmarch walking people off, Manifestations reapplying it, Eternal Nightfall landing with Veil of Twilight up, or Soulbinding finishing. Tank deaths are Chop Down or Soul Sever eaten as a group.
Questions
Who do you fight on The Coiled Altar?
Zul'jan first, then Hex Lord Malacrass. Soulbinding is the lust window. Phase 3 uses both kits. They do not share health. Kill them together. The survivor enrages.
How do you stop Eternal Nightfall?
Destroy Veil of Twilight, then interrupt. If the veil is still up, the hit is a wipe.
Where does Bloodlust go?
Soulbinding, when Zul'jan takes 100% increased damage.