Win duel:
Hold R3 and press L1, R1, L1 to give
player one the win. Hold R3 and press R1, L1,
R1 to give player two the win.

Additional locations:
Hold R3 and press Circle(3) at the map screen.

Additional cards:
Hold R3 and press L1(3) at the deck building screen.
You will get four of each card.

Play as Chuck:
Hold R3 and press L1(3) at the deck building screen
to unlock Chuck in arcade mode.

Play as Shobu:
Select versus mode and let player two choose a character.
Then, have player one press R2(2), L1, R2,
X.


Cards do not run out in duel:

Hold R3 and press Square(3).

Remove shield:
Hold R3 and press Triangle, Square, X
to remove one of player one's shields. Hold R3 and press
Triangle, Circle, X to remove one of player
two's shields.

Add shield:
Hold R3 and press X, Square, Triangle
to add one shield for player one. Hold R3 and press X,
Circle, Triangle to add one shield for player two.

Caitlan:
To get Caitlan, complete Rusty's story.


Chuck:
Get at least one of every card in the game.

Earl:
To get Earl, complete Trey's story.


Jalen:
To get Jalen, complete Rebecca's story.


Knight:
To get Knight, complete everyone's story.


Marcus:
To get Marcus, complete Flynn's story.


Monks:
To get the monks, you must defeat them the first time.


Sera:
To get Sera, complete Luc's story.


Shobu:
Win 100 duels in Arcade mode.

Source:
Win 50 duels in Arcade mode.


Widow:
To get the Widow, defeat her at the end of the tournament.