Gizmo- he has ADD (some of you already know :P)

Lucas- he has lung cancer and was told he wouldn't make it to 27 years old

Matrix- he has multiple personally disorder

Magix- he's afraid of being replaced

Galaxy- she's adopted

Oliver- he ran away from his master (some of you may already know)

Neon- she actually has no self confidence, but acts like it so she doesn't have to talk to anyone about it

Jewel- She's wanted for murder

That's all for now :P