I have some questions about using Pokemon X and Y: If I have Pokemon Y and I put a Pokemon that evolves by trading in Pokemon Bank, then transfer to Pokemon X will the Pokemon evolve or do I have to get another 2DS to trade?
>Pokémon that evolve via trading will not evolve when deposited in or withdrawn from Pokémon Bank.
No, if you put a Pokemon that evolves by trading into Pokemon Bank, it will not evolve when you take it out. You don't need another 3DS/2DS, however. You can simply put the Pokemon you want to evolve by trading into the GTS and ask for the same Pokemon, it won't have your OT and you won't be able to nickname it, but it still works.