[@Kalas] Um...he sounds like a bad person. Everything in his Powers list, to me, makes him sound like a psychopathic murder machine. I get that it's ironic, but "Potentially, Karma could blanket an entire city in eternal darkness though this theory has never been tested" and "Once inside his opponent, the darkness begins to poison the victim, infecting their flesh and mind and essentially killing them from the inside" sound a little TOO ironic. 

It's up to the GM, of course. Just my personal opinion.