Blade 2 Available Cheats:

Daywalker Difficulty
To unlock Daywalker difficulty, go to the main menu, then press and hold the Left Trigger. Then press: LEFT, B, UP, DOWN, X, B, A.

Invincibility For NPCs (Non-Player Characters)
To make all characters you're taking care of invincible (during escort missions), go to the main menu and press the Left Trigger. Then press: X, B, Y, A, X, B, Y, A.

Unlock All Missions
To unlock all missions, go to the main menu. Press and hold the Left Trigger, while you press these buttons: DOWN, UP, LEFT, LEFT, B, RIGHT, DOWN, X

Unlock All Weapons
To unlock all weapons, go to the main menu. Press and hold the Left Trigger, then press: X, B, DOWN, LEFT, B, B, Y.

God Mode
During the game or at the start menu, pause the game, hold down L1 and press Y, X, Y, X, Y, B, Y, B.