The Leafeon Pinkeh

Gallade is a psychic/fighting type, so that would probably work well against Petalburg's gym.

@Blue Moon I'd have to get its mega stone.. and I'm sure if I already have a Mawile but I'm pretty positive I do. It sounds like a nice one to have c:

And I remembered that AS has a LOT of water type pokemon to beat, over half the game is spent on water.. I'll need an electric or at least a pokemon with a grass move. Tentacools and tentacruels are the most common, so a pure grass wouldn't be good agains the Acid. Which is why I picked Roserade, who is half poison

You could always let it evolve into Gardevoir too.