A bunch of blue characters, since most of them have something to do with blue. I got two characters (Ludwig and Yuke) that can cast magic spells so that neat. Green Bob-Omb could be a agile character. Yoshi with wings would be game breaking. Sleet would probably use Dingo to do everything for him lol. So a cast with different abilities, I think it could make a decent game.
Also a few of them are just me with a different name