Okay this may seem a little mean but in the start of the game in order to even have an Oc consindered YOU MUST have an Canon character as well.....
Rules for Oc:
Races:
Angel
Human
Shinigami
Demon
Not acceptable:
Half human/demon
Half Angel/demon
Half Shinigami/human
Half Shinigami Demon
Half Shinigami Angel
Half Angel/human
You get the idea. It's a little harder with the occ on Oringnal's however if you tell me that your character is sweet and timid and she suddenly goes off the deep end....she/he/they are being checked into a mental ward. Keep them in character.