[Suzerain of Sheol]

You actually just reminded me (I might have told you this story before, can't remember) that once, I was running a gauntlet for a friend who'd put together a party he considered very optimized (and they were, in a way), I think they were around level 15. And he was pretty much steam-rolling the encounters I threw at him, but eventually, being as overconfident as he was at that point, he walked into a room with a 15-headed cryo-hydra who won initiative on him and nuked his whole party for 45d6 cold damage, killing everyone but his half-giant fighter. He was impressed.