Shizuka Hio 緋桜閑

The pureblood vampire who bit Zero; even her fellow vampires are uneasy around her. She is called "Mad Blooming Princess" by her fellow vampires. A manservant whom she loved (a former human vampire; said to have never fallen to Level E) was killed by a Kiryu vampire hunter. In retribution, she attacked the Kiryu family, killed the parents, turned their son Zero into a vampire, and took Zero's twin, Ichiru, in as a devoted servant.