For a verbal version of what one lazy tank and one very busy tank have to say about this boss fight, listen to Episode 28 of TankCast, starting at 08:45.
For a written version, keep reading.
Key things to plan for (via Talents, Glyphs, and/or Trinkets):
- DPS cooldowns for Dominator add
- Big physical damage reductions for Reverberating Blow
- Anything to smooth the unpredictable bursty melee hits from construct.
- Reverberating Blow
- If the Construct dies quickly enough, swap every two Reverberating Blows. Otherwise, swap every three.
- Reverberating Blow #1 is very low damage that won’t even need a cooldown.
- Reverberating Blow #2 and #3 (if he’s alive that long) need much larger cooldowns.
- The boss dual-wields, so damage can be incredibly bursty. Just play cautious because you never know when you’ll get hit with 4 melees in 3 seconds and die.
- New in Mythic: Apocolyptic: Not deadly on its own, but combined with everything else it can easily contribute to tank death. Use active mitigation or a minor cooldown to reduce its damage.
- Environmental Hazards:
- New in Mythic: Voracious Soulstalker is an add whose spawn is marked by tall purple swirls and fixates on the closest player. It kills anyone caught in a cone in front of it. All the tank has to do is avoid it and move the Construct away from it if it spawns among melee.
- Green goo: Green goo
- Green swirls: Green swirls
- Tank him on top of the red portal, which spawns dominators. Pick up Dominators when they spawn (a targeting macro is helpful to do this quickly).
- Follow the red portal if it swaps sides.
- Taunt Shadowcallers (casters), if possible, to bring them closer
- Use defensive cooldowns soon after the Dominator spawns, because Gift of the Man’ari will come out soon and hurts everyone.
- Save big damage and offensive cooldowns for the Dominators.
- Voracious Soulstalker, from Phase 1: use construct’s trap. Don’t forget to reapply it when the duration is almost out.
- Draw a straight line from boss to portal to lay down Fire and slow Haunting Souls. Avoid walls because they make things weird.
- Drop apocalyptic felburst on the Dominator when it spawns, but warn the raid because they’ll die if they’re standing in it.
- orbs to AoE Haunting Souls. You can usually get 2 orbs off before they reach the raid.
- Otherwise: smashy on the boss.
- Your rotation might look like this: trap > charge > smashy > burst > orb > trap > smashy > orb > charge