The builds listed here are all assuming you have acquired your 4-piece tier bonus from Sepulcher. It is important to note that certain builds do change upon 4-piece acquisition so I encourage you to check the spreadsheet listed here (under the sims tab) if you have not yet acquired tier.

All legendary recommendations are also assuming you are playing 1 Covenant legendary baseline. I did however list Decaying Soul Satchel (Night Fae) in a few places you might play it over others before acquiring your second legendary.

Recommended Spec: Any

Multiple waves of adds with some priority based cleave. Boss is active from the start on mythic.

Legendaries

Demonology: Wilfred's Sigil of Summoning

Affliction: Relic of Demonic Synergy/Wrath of Consumption/Decaying Soul Satchel

Destruction: Wilfred's Sigil of Summoning

Recommended Spec: Demonology

A single target fight with periodic, heavy movement and avoidable ground based mechanics.

Legendaries

Demonology: Wilfred's Sigil of Summoning

Affliction: Malefic Wrath

Destruction: Madness of the Azj'Aqir

Recommended Spec: Demonology

Phase 1 is single target with multiple adds spawning in phase two which repeats three times. Certain adds need strong prio cleave.

Legendaries

Demonology: Wilfred's Sigil of Summoning

Affliction: Relic of Demonic Synergy/Malefic Wrath

Destruction: Madness of the Azj'Aqir

Recommended Spec: Demonology

Mostly single target with a cleave add spawning every so often. Add has as pretty low health pool and died early into cleave. 

Recommended Spec: Affliction/Destruction

Perma two target fight in phases 1/2 with adds spawning in phase one. Phase three is perma four target which brings very strong Affliction/Destruction cleave potential.

Legendaries

Demonology: Grim Inquisitor's Dread Calling

Affliction: Relic of Demonic Synergy/Wrath of Consumption/ Decaying Soul Satchel

Destruction: Madness of the Azj'Aqir

Recommended Spec: Demonology

Phase 1 is single target however phase two has multiple priority based cleave mobs and the potential for stacked AOE. 

Legendaries

Demonology: Wilfred's Sigil of Summoning/Grim Inquisitor's Dread Calling

Affliction: Relic of Demonic Synergy

Destruction: Madness of the Azj'Aqir

Recommended Spec: Any

The fight has been overhauled since our last testing and the cleave pylons have been removed. Fight is heavy movement at times which means Affliction could bring hidden value. 

Legendaries

Demonology: Wilfred's Sigil of Summoning

Affliction: Relic of Demonic Synergy/Malefic Wrath

Destruction: Madness of the Azj'Aqir

Recommended Spec: Demonology/Destruction

Fight is a mix of single target, cleave and hectic priority based cleave. Destruction can bring a strong cleave based profile while Demonology can bring a strong funnel/stack AOE based profile. 

Recommended Spec: Destruction/Affliction

Fight has not been tested however appears to be a two target cleave based fight which makes both Destruction and Affliction good choices. Destro may pull ahead due to its AOE profile in phase 2.

Legendaries

Demonology: Wilfred's Sigil of Summoning

Affliction: Relic of Demonic Synergy

Destruction: Madness of the Azj'Aqir/Wilfred's Sigil of Summoning

Recommended Spec: Demonology

Fight has not been tested however seems to be predominantly a single target based encounter with potentially a bit of small add cleave. 

Legendaries

Demonology: Wilfred's Sigil of Summoning

Affliction: Relic of Demonic Synergy/Malefic Wrath

Destruction: Madness of the Azj'Aqir

Recommended Spec: Demonology

Fight has not been tested however seems to be predominantly a single target based encounter. 

Legendaries

Demonology: Wilfred's Sigil of Summoning

Affliction: Relic of Demonic Synergy/Malefic Wrath

Destruction: Madness of the Azj'Aqir