Diabolik Lovers Assasin

I hunt in the shadows killing every vampire I see I have the ability to turn off my humanity for a kill but that's because I almost lost it a long time ago.My name is Serena remember it cause not many people know. I have a terrible past my dad killed my mom and then committed suicide and that was the seed to the destruction of my whole family.Figuring out Vampires had a huge part in the destruction of my family my goal was to kill them all but I later realized that my cousin Yui was still alive...with vampires and I am going to save her even if I end up dying in the process...or worse