This takes place after the incident with the Impure King (Blue Exorcist season 2) I do not own Blue Exorcist Rin returns to school shortly after the Impure King incident when he meets Seraphina, he see her with Amimon. Shortly after Rin meets Seraphina he learns he is turning into a deeper form of a demon. Everyone had enemy's Rin and Seraphina just have more than usual. What happens when Rin learns Seraphinas enemy is none other than the King of Rot Astorath, and he is out for revenge on both Rin and Seraphina. Juts saying I really suck at summaries so I promise the fanfic is really good