You're a mentally unstable vampire with very powerful dark magic, but why wouldn't you be? You were seriously abused and verbally abused as a toddler or a kid (it depends on how old you wanna be) by your by your mother, who is now dead because you killed her with your magic. You live in a creepy ass, emo, gothic, victorian estate with your older siblings who are Lucifer, Alfred, Isabella, Lazarus, Sebastian, Lilith, and father Victor.
You all have different mothers who are all now dead, but the same father, whose name is Victor Kirkwood, and he's the vampire emperor. Your mothers abused or verbally abused you and your siblings as toddlers because Victor was never around because of his job as vampire emperor, and they blamed you guys for it. So you all grow up as sadistic, sinister, ruthless, mentally unstable kids.