Levi Ackerman is the son of Lucifer Ackerman, aka Satan, the Devil, et cetera. When this demon gets tasked with trying to convert an angel into a fallen angel, or a Castaway, he is met with his prey, Eren Jaeger. The bright eyed angel of light isn't what the raven expected and the two fall for each other. Will the concept of Eren's transformation cause the star-crossed lovers to separate or will Levi remain selfish and keep the brunet all to himself? DISCLAIMER: The characters in this fic belong to Hajime Ishiyama unless specified otherwise.