Vampire Killer (Deep Blood).Tōma and Stiyl find Aureolus at his office, along with Aisa and Index, who is still asleep. It is revealed that Aureolus was Index's partner three years ago, though devastated that her memory needed to be erased. He intends to use Ars Magna along with Aisa's powers to save Index by turning her into a vampire, which will overcome Index's one-year life expectancy. However, Aureolus, distraught when he realizes that Tōma had already succeeded this by using his Imagine Breaker, uses Ars Magna against Aisa, Stiyl and Tōma. Nonetheless, this reality-distorting magic finds itself useless against Tōma's Imagine Breaker. When Tōma realizes that Ars Magna cannot alter reality, but rather makes Aureolus's thoughts come into it, he manipulates Aureolus into fearing him, which ends in Toma's arm changing into a dragon and Aureolus passing out from fright. Tōma winds up in the hospital again to have his right arm reattached after the battle, and Stiyl visits him, explaining that Aureolus lost his memory and powers. He disappears when Index and Aisa come to visit, and Index reveals the Church will now take care of Aisa. When Aisa learns why Tōma saved her life, she smiles at him.