When Muzan's current uppermoon 1, Kokushibo, gets kidnapped by the anti-demon clan, he has no choice but to replace him with someone that might be as competent and as strong as him. But.. she had history with the demon slayer corp? Will they be able to save the real uppermoon 1? Will Mizuki, the replacement upper, find the truth? AU Inspired by krazedream's Third Party AU on Youtube. Please go check it out, she's amazing ;))
4 parts