Kessen

Play as the West:

Successfully complete the game with the East.

Battle mode option:

Successfully complete the game with the East and the West and a new battle mode option will be unlocked on the menu. Thus, mode allows you to fight any previous battle, with either East or West.

Unlimited Special Maneuver +Invisibility:

During game play, pause the game and hold L1+L2+R1+R2 and press down, left, up, right, x, circle, triangle, and square quickly.

Then without un-pausing or saving your game, restart your ps2. Then load your game and you will have unlimited special maneuver and invisibility.