We are in Hell. We have killed all of the summoned creatures, knocked Irenicus out of slayer mode and have been hacking on him for ten minutes, causing between 4 and 56 points of damage, yet he won't die. What gives?
That happens sometimes. I'm not sure what the the cause is, but sometimes powerful enemies just won't die. It happened to me with Sendai and Draconis. The only thing I know that works is reloading and thus, restarting the fight.
She says: Lou, it's the Beginning of a Great Adventure