Seraph of the End, 3 (novel)

Not only Guren but his closest allies among the Imperial Demons have accepted forbidden power, and the merciless Hiragi Clan orders them to go after its once-favorite but treacherous daughter Mahiru. The vampires, however, are ready to show that no human faction stands a chance against them. Christmas is finally here, an apocalyptic time of year for all good boys and girls.