Legacy Unbound (AoT/Blue Exorcist crossover fanfic)

While on a mission with Levi, Eren,and Mikasa, Armin is eaten by a Titan. But he is then saved by Mephisto, who takes an interest in the little blonde boy for he believes Armin has an untapped power. Mephisto offers Armin a chance to become stronger by becoming a student at True Cross Academy and learn the ways of an...