Forbidden Angel

She was born of a forbidden love between two races, demons and angels. Not really belonging to either God or Satan, she has no place to go when she dies. So, in a meeting that went better than expected, God and Satan agree on a solution. She was to train with Thanatos, the name given to the Greek god of Death. She would work with him in Purgatory, and enforce any judgment that was laid down. But a problem develops: someone has kidnapped Thanatos, and is holding him captive. With no souls moving through Purgatory, her job is on hold. Finally, she gets to go back to Earth, but on one condition: find the being that dared kidnap the god of Death himself.