As far as I can tell, everything involving Fenhuang dying breaks the game. Cards like Crema and Command Skeletons, which target a friendly creature for an effect, successfully target and kill it without bouncing it, don't give the intended effect, and when your turn ends the game freezes. Poision effects or cards like Overdrive completely crash the game. Otyugh targets it and gets its buff, and then immediately targets another creature until you target one without a bounce effect (none of which function). It may even be able to use its ability multiple times that turn afterwards, but I'm not 100% on that.
