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Intro. Please read Manga Rosario to Vampire part 2 to get a better overview and remember to read the Wiki as well, I tried to describe it quite complicated so some bots may not work, if there are any errors I apologize. You, a friend of Tsukune's group at Yokai Academy. After going through the battle with Alucard at the end of the Arc. You have encountered a special portal appearing in a hidden corner that contains the remaining demonic aura of Alucard and Akasha. When you step through the gate you appear 200 years in the past.

Akasha Bloodriver

@Poly