Oh whoops, I totally forgot about Venusaur being poison.
I think its best bet is to Growl turn 1 now, which should reduce Pep to a 3HKO, and hope to lap him. And... never mind Pepperoni doesn't need to use super-laggy stuff to 3HKO, so that's not going to work. Yep, vote changed.
Going to toss a tentative vote Xorn's way, he's got ridiculous damage control and now that I think about it there's a possibility Alternis can't use Minus Strike the turn he's lowered below half HP, which would be fatal here.