Duel Masters PS2 Cheats!
When you see the code combination, remember that you must be holding down R3!
X, Square, Triangle Add One Shield to Player 1
X, Circle, Triangle Add One Shield to Player 2
Triangle, Square, X Break One of Player 1's Shields
Triangle, Circle, X Break One of Player 2's Shields
L1, L1, L1 Do it on the Deck Building screen. Get 4 of every card in the game. Also unlocks Chuck for Arcade Mode.
Circle, Circle, Circle Do it on the Map Screen. Unlock all Locations.
L1, R1, L1 Player 1 Wins Instantly
R1, L1, R1 Player 2 Wins Instantly
Square, Square, Square Turn off Deck Outs
Caitlan Successfully complete Rusty's story to unlock Caitlan
Chuck Get 1 of every card in the game.
Earl Successfully complete Trey's story to unlock Earl
Jalen Successfully complete Rebecca's story to unlock Jalen
Knight Successfully complete everyone's story to unlock Knight
Marcus Successfully complete Flynn's story to unlock Marcus
Monks Defeat the Monks the first time to unlock them
Sera Successfully complete Luc's story to unlock Sera
Shobu win 100 duels in arcade mode
Source win 50 duels in arcade mode
Widow Defeat Widow at the end of the tournament to unlock her
Hope this helps!