Debug-mode
Go to aNY terminal while playing, then replace the disc with another PlayStation2 game. Depart the terminal, wait for the debug screen to appear, then replace the original game disc.

Sidestep
Just hold L1 + R1 and move the Left Analog-stick Left or Left Analog-stick Right and your character will start to sidestep. Also by moving the Left Analog-Stick Away, your character will move away with his back to the camera. Note: This will not work at places where you are unable to rotate the camera with L1 or R1.

New Game
Finish the game, then start a second game with a cleared game save. You will now be able to replay a game with the Demonic Compendium, and have the ability to change costumes, and no level limit on fusions and summons. Then press Select to switch between first person and third person view.