Fight Anger with Anger

Each small Sha (Spawn of Anger) killed grants one stack of Uncontrolled Anger, which refreshes to a maximum of 30 seconds per kill and stacks up to 20. As soon as you enter the instance, head straight to the pool area and kill the 40 small Sha there, which will passively build your 20 stacks. On the way back through, drag any unaggro'd Sha with you and kill them one at a time to keep the buff refreshed.

In the final room, there is a lower platform with three groups of mobs and an upper platform above it. Kill the first group on the lower platform, then kill the group on the right side. The adds on the right keep spawning until the central mob is killed, so leave that mob alive to farm up to 20 stacks if needed.

Head up the right stairs and kill the group of three large mobs on the upper platform. On the left side of the upper platform there is a group of one large mob and roughly four small ones — these can be used to refresh your Uncontrolled Anger stacks during the boss fight. On heroic, assign one player to continuously kill the small Sha from this group to keep stacks active on the group.

With 20 stacks of Uncontrolled Anger active, immediately pull the Abomination of Anger. Have a ranged player or healer pull small Sha toward the boss so there are always 2–3 nearby to kill and refresh stacks throughout the fight. Alternatively, wait until the boss is at 10% health, then kill Spawns of Anger one at a time without killing the Shadows of Anger — all players receive the debuff stacks — and once you reach 20 stacks, finish the boss before the buff expires.