about the ocs

gyomei himajima is the stone hashira of the demon slayer corps what happens when he goes missing. The hashira finds gyomei but he is not the same he became a demon their enemy now they have to kill him but none of them are strong enough to do so. Gyomei is a demon now and the hashira are only eight now that gyomei forgot all his memorious with the hashira. What happens when gyomei fell in love with one of the hashira and remember everything about his past. Will this be like a nezuko case or not will he help the demon slayer corps or muzan.