Umbrage for Umbriss

Level 100 solo - Face-pull the boss DO NOT HIT HIM and run around until a Malignant Trogg spawns. Run to the Malignant Trogg with the boss in pursuit and kill the Trogg near boss. Then, turn and nuke the boss....well done.

When you engage Umbriss, a set of 4 Troggs will spawn, including one Malignant Trogg. The Malignant Trogg can be crowd controlled using Hex/Poly off to the side before it even engages. When a Malignant Trogg dies, it places a debuff on Umbriss which only lasts for 20 seconds but increases the damage he does. Keep the Malignant Trogg cc'd while burning down the boss and adds. Do note the adds will continue to chain spawn (minus the Malignant Trogg) until he enrages.

At 30%, Umbriss will enrage dealing a significant amount of extra damage. Your group should continue to DPS down Umbriss until he is at around 15% before 'waking up' the controlled Malignant Trogg and killing him next to Umbriss. This will apply the 20 second debuff to Umbriss and give you enough time to dps him down for an easy achievement completion.

Easy tactic:

1. 
   
2. Hex, Repentance or Polymorph the Malignant Troll (purple, shadow priesty one) and keep him out of the fight and re-CC whenever needed.
3. 
   
4. Get boss down to 5%.
5. 
   
6. Then kill the CCd troll near Umbriss so that he gets the buff.
7. 
   
8. You have 20 sec to burn the boss down now.
9. 
   
10. Profit.
11.