This is why I like the Infernal Council fight. Everyone needs to solo an easy mini boss. This fight should be first instead of 4th because it determines if everybody is geared.
We took an undergeared marauder thru and on this fight he died or timed out everytime. His gear wasn't even that bad, he had almost 15K hitpoints.
We tried him on the Healer and he kept dying. We moved him to the one with the next lowest hitpoints and he would get closer to killing him before dying.
Luckily on the 6th try, Another player got there just as he got killed and got off a 6.5 k crit to finish his boss.
One of his abilities heals the group slightly, giving him the no-damage debuff. Happens to marauders everytime.