Enable the "Multi-player arenas" code. Select any arena, then exit out of it. Load a saved game and begin game play in story mode. Press Start on controller two when a major character is encountered during game play. If more than one major character is encountered in a scene, press Start to scroll through those that are controllable. Controller two can now be used to control that person. Press Back on controller two to stop controlling them. Note: You can also control Bosses.