Fight Clonus Opponent:
While selecting an opponent at the character selection screen, hold Select to fight against the Clonus version of that character.

1st Person Mode:
While playing a 1 player game, press and hold L1, L2, R1, and R2. While holding,
press diagonal right down. If done correctly,you should be in 1st person mode.
Do the exact same thing to turn it off.