TL;DR
4.1. Tanks
- Taunt swap after each Might of the Void combo, when the other tank has two stacks of Void Lash.
- Aim Void Lash away from other players.
4.2. Healers
- Have raid cooldowns ready for Surging Darkness.
- Be aware of where players with Roiling Deceit are running, as they will likely be out of range while dropping off their debuff.
4.3. DPS
- Burst down Silithid Warriors before they are able to damage the raid.
- Save cooldowns for the final phase if you are assigned to catch the Orb of Corruption.