I went to Trial of the Champion Heroic with Exëcute, Songlala and Jinjersnaps (on Rustytaps). No Eadric the Pure for The Faceroller. But we still could do the last achieve I've Had Worse against the Black Knight.
I've Had Worse - The plan was simple. Nuke the first Ghoul. Then in Phase 2 AoE down all the other Ghouls to prevent them exploding. This time it worked and the Ghouls were all dead in time.
Then we just killed Black Knight and the Achievement popped up!