Medusa infiltrates onto Ryo's school as a teacher named to make him remember he is Dante. She also helps the Satanists to kidnap Ryo's sister, , whom they want to sacrifice in a Black Mass. When Medusa is captured by God's Soul, Ryo helps her when she convinces him she is the only one who can save Aya and tells him he is Dante's reincarnation. Medusa and Ryo arrive in the Black Mass just as the Guardian Justice attacks the ritual and prevent Aya's sacrifice. Amidst the conflict, the Satanists summon a mindless demon Dante, who cannot distinguish between friends or foes and eventually eats Ryo. Ryo reappears on Demon Lord Dante's forehead and realizes he controls its body. Shocked, Ryo denies being a demon and releases himself from Dante's body, which makes Dante disappear and transform Ryo into a human-like demon. He returns home after being defeated by traitor demon Zenon but when footage of him in Dante's body is shown on television he flees from his home.