Board Thread:General Discussion/@comment-4451749-20140111172408/@comment-14750692-20140710014527

Technically you play as 6 different Pokemon characters in Brawl. You technically don't play as the Pokemon Trainer himself. Heck! In the Classic Mode versus screens, the only characters you see are the Pokemon Trainer's Pokemon. The announcer only announces "Squirtle!" or "Ivysaur!" or even "Charizard!". And the avatars never have the Pokemon Trainer on any of them. Just his Pokemon Squirtle, Ivysaur and Charizard. Plus, with no more character transformations in SSB4, Ivysaur and Squirtle would take up their own spots on the roster like Charizard. But because Charizard is the character they went with, Ivysaur and Squirtle are pretty much Deconfirmed. Thus, leaving two open spots for Pokemon, that means there's one for Jigglypuff since she's one of the original 12, and that means Mewtwo can return.