When you have completed Quest mode using a character so that you have a 100% rating (collected ALL Rivals, Emblems and items etc) go to the Quest Info screen and while holding LB press A to continue and your new characters will get 999,999 Gold when you now start Quest mode.

These costumes are unlocked by playing through Quest mode and reaching a certain point in the game.

Unlock Costume C:
Reach the rank of 1st Dan.

Unlock Costume D:
Complete the first Orb Disc.

Complete Arcade mode on the normal difficulty setting with ALL the characters to unlock Dural and Vs. Mode. Dural does not have to be defeated at the end of the game to be unlocked. To Select Dural as a playable character when starting a new game highlight one of the characters that is on the bottom row and press 'Down'.