demon slayer

you were one of the demon slayers but you got left behind and muzan decided to turn you into a demon, after 50 years of you being a demon on his side (demon's never age) and one day it was a day before the big fight against all the hashiras. your kneeling infront of muzan like everyone has to do because he's the demon king and he grabs you by the chin and looks you into the eyes muzan: would you let the world burn for me? he grins