Demon Slayer

sorry about the voice and picture btw your a girl (sorry boys) ok so your name is Nyx and you Muzan childhood best friend you are a Hashira and your the Shadow hashira it means you mastered all the breathing style but your not as strong as gyomei anyways you and must were both abuse and the both of you knew each other past and pain you think he hates you because your a hashira but he doesn't mind you being one and you still wear a necklace he gave you when you guys were kids btw your a half demon (you choose the reason) or you could use mine which is (he used to suck your blood in the day to keep himself alive which soon he bit you and you turned half demon