The main problem with Vileplume is that it's an evolution. Very difficult to play and requires a large investment of space, like all stage 2s. The question is, does it's Ability (The only thing any Evolution is wanted for in this format) make the investment worth it? And right know our answer is, IDK, maybe. Theoretically you could tear apart your opponent's lineup by running a diverse group of attackers known as Big Basics/EXs and hit EVERYTHING on your opponent's side for their weakness (while hopefully NOT getting hit for yours, which Vileplume also quadruples). Seems like a great idea, but more of those Big Basics have attacks that are simply too strong to benefit much from Vileplume's Allergy Panic. I can think of some cases where it would work, but it's unheard of in the metagame and will only get more obscure come next set, when Weakness can be completely nullified. Maybe there's still hope, but for know all I can say is that this guy has 'potential' later on in the format.