Survival mode:
Get a "4D" or greater rank in battle during game play under the normal difficulty 
setting.

Time attack mode:
Get a "4D" or greater rank in battle during game play under the normal difficulty 
setting.

Play as Black Rahxephon:
Successfully complete the game with the Cross storyline to unlock Black 
Rahxephon in survival or time attack mode.

Play as Male Rahxephon:
Successfully complete the game with the Terra storyline to unlock Male Rahxephon 
in survival or time attack mode.