Kojou has finally defeated the Blood, but with Ren abducting Avrora and fleeing to another world, there's no time to celebrate. And with Kojou's vampiric powers gone, staging a rescue seems impossible...until the First Primogenitor, Ki Juranbarada, shows up with a striking proposal and a tempting offer-a new set of Beast Vessels. But when Juranbarada's gift transforms Kojou into a monster devoid of reason, it's up to Yukina and company to find a way to save him before it's too late!