Hi, I need some help, I can't remember the name of an oneshot!

It was about vampires I think, the protagonist was a human girl with long and black curly hair. The dude had a light haired bob cut (I don't really remember if he was a vampire but he was weird, lived in a castle and killed women) and he was kinda crazy and a bit agressive. I think she knew him from before? I don't really remember, but she was special.

At the end he stabs her and she becomes a doll, and then he dies too hugging her (doll)

I'm not really sure if this is right but if something is close it helps! Thanks!

Yes! I love you!

Thank you so much :'D