yup it works. I use it all the time on Firemaw. Good combo is massochism on Firemaw and running your champs in for a boosted maddenning echoes on their champs to kill off their guys. It could cause 38 dmg to the group affected.
Phoenix Anklet in ST also grants Immortality. Actually, it's pretty interesting... it prevents Firemaw from dying the first time it would, refills its HP to full, gives it Immortality, and Short Lived 1. So, you get a few more rounds of wailing away with your Firemaw, and when he dies from Short Lived or from being killed, the fire damage procs, you get the relic, and he also goes back to your tray. Too bad there's no good fire synergy in ST -- and too bad Firemaw + Anklet costs so much. C'est la vie.
