Strike the Blood, Vol. 22 (light novel)

"THE FINAL BATTLE... To save Avrora, Kojou lays it all on the line and gives up his Fourth Primogenitor powers...but the battle is nowhere near over. The Encroachment of Nod begins, and Shahryar Ren's true ambitions are revealed: to restore the Deva legacy for world domination! Facing the overwhelming might of the Beast Vassal Warheads, the only option seems to be the destruction of Itogami Island-a task assigned to Yukina Himeragi! Torn between duty and friendship, Yukina is tormented by the decision she is forced to make. Things seem dire, but Kojou Akatsuki's not done yet! There are other ways for him to gain power... and he's determined to rescue Avrora from Nod. With the support of primogenitors, Attack Mages, Mogwai, and more, he and his friends brace themselves for the battle that will decide the fate of the world."--