This imo gives Phoenix some important niche ability that would increase his pick rate at all levels. Kayo for as good as he is can't stop a viper lineup because you don't know where she is, but allowing Phoenix to nullify Vipers poison for defuse would change everything and increase his pick rate at all levels. Now to be clear only Snake Bite, if she combines it with Poison Cloud then the combined vulnerability should win. In either case, even if it's just Snake Bite he's still vulnerable so if she peeks it(which she'd now be forced to do if Phoenix is alive) then she'd have the edge in the duel.

Thoughts?