Blaze
To unlock the game's boss character, Blaze, go to the Krypt, then move to the "?" box. If you have a GameCube controller plugged into the Wii, type in the code "Y, B, Left, L, Left, X." If not, plug in your Classic controller and input this code: "X, Y, Left, L, Left, A." You also earn Blaze when you find 50 Relics in Konquest mode.
Taven
Fans of the demigod Taven must go to the Krypt's "?" box, where the code you will need is "L, Left, Z, Up, X, Down" on the GameCube controller. Alternately, typing in "L, Left, Z, Up, A, Down" on the Classic controller has the same effect. You can also play as him after finishing the Konquest story mode.
Daegon
To play as the main villain of the game, Daegon, you'll need to return to the "?" box in the Krypt and type in either "R, L, Y, Down, Down, B" on the GameCube controller or "R, L, X, Down, Down, Y" on the Classic controller. If you manage to collect 30 Relics in Konquest mode, you will also unlock him.
Meat
Again at the Krypt's "?" screen, type in "Up, B, B, X, X, Up" on your GameCube controller or "Up, Y, Y, A, A, Up" on the Classic controller. These codes unlock Meat, the skinless wonder. If you'd rather earn him the hard way, gather 10 Relics in Konquest mode.
Shinnok's Spire
Use the following codes to unlock the Shinnok's Spire arena: for the GameCube controller, "Left, Left, X, Up, Y, L" or "Left, Left, A, Up, X, L" on the Classic controller.
Falling Cliffs
The "?" box code "Z, X, B, A, X, Y" on the GameCube controller, or "Z, A, Y, B, A, X" on the Classic controller unlocks the Falling Cliffs Arena.
Krimson Forest
For the Krimson Forest arena, use the GameCube controller and type in "X, L, Up, B, X, Down" at the "?" box. The Classic controller code is "A, L, Up, Y, A, Down." Savvy players may recognize this as the Red Dawn arena from other versions of the game.
Nethership Interior
Type in either "R, Left, Left, Down, L, B" on your GameCube controller or "R, Left, Left, Down, L, Y" on your Classic controller at the "?" box to fight inside the Nethership.
General Reiko's Map Room
At the "?" box, use the GameCube controller code "Z, Y, R, Up, A, A" or the Classic controller code "R, X, R, Up, B, B" to see what's in General Reiko's Map Room. Or, more accurately, destroy what's in General Reiko's Map Room.
Pyramid of Argus
The codes you will need for the Pyramid of Argus are "R, L, B, A, Z, Up" on a GameCube pad, or "R, L, Y, B, R, Up" on the Classic controller.