This is Danissa “Peony” Carter. In her past life, she was Scorpio, and ruled over Pluto all by her lonesome.
She, along with her younger sister Cappelia (the Capricorn), were born on Earth quite some time ago as normal human girls. Of course, one day Cappy went and ruined things, first by getting turned into a vampire, and then turning Peony into a vampire.
As a vampire, Peony is cold and unpredictable, and quite prone to random fits of violence.
She joined Regal’s little Zodiac scheme at the same time as her sister.