Louie G.
Smash Legend
I think that K. Rool would bring something new to Smash that no other character does.I think the odds he comes packing at least a Kaptain costume, and maybe a Baron one, are higher than those of other characters, since costumes are a far more central aspect to K. Rool's character than they are to the vast majority of other characters. With most protagonists, costumes are a temporary power-up or gimmick; with K. Rool, he changes costume and the entire theme of the game shifts as a result. It's also an endearing quality of his that sets him apart from the other villains and heavyweights (and characters in general), so yeah.
His costumes can affect his gameplay.