Sword of Mikaela Hyakuya in Seraph
Mikaela Hyakuya is one of the protagonists of the Seraph of the end series. He is a half-vampire and a servant of the Third Progenitor, Krul Tepes. He was human but she forced him to drink her blood. He, along with Yuichiro Hyakuya, is possessed by the "Seraph" gene.