Oscar is a angel wo was betrayed and left to burn by heaven that without God had become corrupt. 

Oscar is a very kind, understanding and nice person but he can and will fight if he has to. 

After many strange events he has kind of become a member of the Porcelain Circus even if he does not take part in their soul collecting.  Oscar has really grown to care for Stitch, ribs, jinx, links and even silk. And Oscar has realized how much is wrong with heaven. 