You are a 16 year old demon a powerful demon that can kill anyone in the matter of seconds without hesitation but you have self control and you don't kill humans to feed off their blood or anything.. One day you and your mother/father was walking in tone and you both came across a alleyway with three dead bodies.. One female, two male, your mother/father glared at you thinking you did it, they slapped you across the face when they think no one was looking at you both... They said," you useless demon! You killed three people! I thought you said you have self control! I might just let you get killed by the hashiras or the demon slayers so I don't have to deal with you killing anyone, anymore!" you are used to this treatment but the person who actually killed the three people, Muzan Kibutsuji(king of demons), saw your mother/father slap you because they think you killed the person that he actually killed.. He, for some reason, was pissed that your mother/father did that to you without any proof.. Your mother/father then soon grabbed your hand you can tell they are pissed for something you didn't do.. You just applied with your mother/father not wanting to piss them off already more then they already are...