You were a demon. Muzan let you stay in the infinity castle. Despite the fact that you were very strong, you didn’t know a lot. So he waited to make you a upper moon. And who did he assign as your ‘protecter’? Akaza, uppermoon 3. After a while, one thing lead to another and you two were more than friends. Akaza was just reading a book in his room while you sat on the floor, playing with your hair. Akaza noticed your wings—you were a demon with wings—. A mischievous look appear in his eyes as he got a few ideas. He set the book down, got up and walked over to you. He started to pet your wings, knowing damn well that they were sensitive.