It is revealed that Arcueid is a royalty amongst vampires; she was created by the True Ancestors as a weapon and had never experienced joy and life as a normal person until she met Shiki. Her intended use was not known, but it eventually became to combat Roa Valdamjong, the Serpent, a vampire who found true immortality: reincarnation. He had fallen in love with her, and found reincarnation as a way of living life by her side; this backfired, as she could not experience emotion.