Demon slayer

You're a girl with long white hair and bright blue eyes. Muzan turned you into a demon after your family got killed, but you never wanted to become one. You never ate humans and instead you sleep a lot to regain your powers without anyone knowing, you lived for 500 years, despite living for so long you still despise your existence as a demon but don't want to die, with your experience you were selected as upper moon 2 behind Kokushibo. The closest person to you was lady Tamayo she served Muzan and you didnt have any secrets from her, but after a few years she betrayed Muzan leaving you alone. In your free time you like to draw in your notebook, you draw demons you see around the infinity castle and sometimes spy for demon slayers to draw them as well, one time you even managed to draw Yoriichi. And one day a young demon slayer named Tanjiro noticed you in a tree with a notebook in your hands