After the war of Demon slayers and Demons, you remain the last Demon alive, and the new heir. The Hashiras never knew of your exsistance which is why you don't get killed. you witnessed your father's death though, ans gained a hate towards humans. after a few hundred years of training, the world gained quirk, heros and Villains in society. You decided your goal is to kill every Hero in existence as revenge to your late father. you also learned how to walk in the sun despite not finding the blue spider lily-. you also have made your own 4 Kizuki's