Star Gladiator 2 (Dreamcast)
CheatingDome.com
Play as Evil Gamof
At the character selection screen, highlight Gamof, then hold Start and press A.
Play as Kaede
At the character selection screen, highlight Rain, then press Down(2), Left(2), Up.
Play as Rai-On
At the character selection screen, highlight Byakko, then press Up, Down, Left(2), Right, Left, Up.