Strike the Blood, Vol. 21 (light novel): The Twelve Blood Servants

A RACE AGAINST TIME...Kojou has finally defeated The Blood, but with Shahryar Ren abducting Avrora and fleeing to another world, there's no time to celebrate. Since Kojou's vampiric powers are gone, staging a rescue seems impossible…until the First Primogenitor, Ki Juranbarada, shows up with a tempting proposal: He'll grant Kojou a new set of Beast Vassals if he agrees to put Ren's ambitions to rest. But when Juranbarada's gift transforms Kojou into a monster devoid of reason, it's up to Yukina and company to assemble twelve Blood Servants and quell his raging powers before it's too late!