To change costumes, go to the character and press Up or Down. You will be able to select a different costumes. Some characters may have three choices but most have only two.
Matthewb22.
When you go into the arena selection screen and have highlighted the stage you want to fight at, press Y. The stage will be selected, and you will go to a different arena. Red Ribbon Base is the only arena that is actually in a different area. All the other stages, except for Planet Namek, the Hyperbolic Time Chamber, and the Kai's planet (the one with the sword stuck in the hill) are a different time of day (either dusk or night, depending on the stage).
Alternately, defeat Majin Frieza or Majin Cell in the same manner.
Leded.
If you defeat someone when the dizzy symbol is over their head, you will take away two life points. This is what makes it possible to get Babidi's Mind Contol (Majin Vegeta).
Jimmy.
On the level were you must stop Majin Buu from being resurrected, kill Cell or Dabura to get Babidi's Mind Control for Vegeta.
josh davis.