Doomvoid Guillotine: Column AoE across the arena. Move away from the oncoming Nyx that spawn.
Doomvoid Slicer: Stack under boss, then move to diagonals to avoid more Nyx.
Shadowflame: Buster on both tanks.
Dark Fire III: Large AoE markers on multiple players.
Unholy Darkness: Stack marker on one player.
Spell-in-Waiting: Delays the effects of the next Dark Fire III, Unholy Darkness or Shadoweye. Players targeted for those abilities will have clock-like markers overhead, changing to a 5-second "dice" countdown shortly before the ability really resolves.
Entropy: Moderate raidwide.
Empty Hate ("The Hand of Erebos manifests!"): Knockback: move close to the hand outside the arena.
Punishing Ray: Purple pillars spawn; one player must stand in each, soaking light damage.
Shadoweye: Gaze marker on one player; others should face away. The marked player should try to move behind the group before it resolves, to avoid forcing everyone to interrupt DPS.