Some Celestials were turned into Bloods in the Sourcecode Project, they lost their ability to reproduced and in return, they gained immortality and super strength. Not all were accustomed to this change, Carl was one of them. 

    Once a student in the Research Institute, Carl favors knowledge over violence. However, after his mutation, he accidently killed a Demon, which gave him a pleasure unlike any he had experienced. He became a bounty hunter not for gold, but to quench a mysterious thirst.