Well done, I've never played the game like that relying on allies to that degree while having no player damage, that's kinda untested territory. I sort of tried to build the bosses around combating different playstyles, but I don't know whether it turned out like that. After a quick double check it seems like they all chew through your allies at fairly different rates, surprisingly the northern boss seems to be the one who is the poorest at killing your allies despite firing 10 billion projectiles. While the eastern boss is the best at it, however the eastern boss was designed to fall quickly to builds with high Energy/Frenzy so it's balanced like that.
Using lifedrain on bosses sounds like some silly gameplay though lol, maybe I shouldn't have allowed that. I think I prevented bosses from being rot (poisoned) because I like to avoid tedium. But then again, having freedom in playstyles for the sake of fun is a good thing too.