To access these modes enter the combinations at the title menu. Remember that cheats get disabled when accessing online gameplay, and don't affect Trophies. More than one code can be active at once.

Effect	Code
Player 1 God Mode	Up, A, X, B, Y, Down
Player 2 God Mode	Down B, X, A, Y, Up
Slice Mode - Enables all strikes to cause dismemberment	LT, X, A, X, A, RT
Sudden Death - All warriors start the round with critical health	X, RB, Up, Down, LB, A
Zombie Mode	Y, A, A, A, X, B