[Crossover] Tanji Zhi Wants to Kill Them All

The will of the world tried to save itself by raising three saviors. The first savior was killed so many times and suffered so much that he lost hope and destroyed himself. The second savior had such an overpowering aura and so many cheats that he was forcibly banned. Only the last one managed to save the world, barely, but then went dark because of her poor mental state. After inheriting Kibutsuji Muzan's will and legacy and becoming the Demon King, Kamado Tanjiko went through 999 cycles of reincarnation and finally wiped out the Demon Slayer Corps and everyone connected to it. She thought she could finally enjoy some peace, but then she discovered... Why was that charcoal seller 99% similar to her? Why did the Demon Slayer Corps still exist? Why was Muzan still alive? Why were there still lingering threats? Why did she still have to work overtime? Tanjiko expressionlessly draws her Nichirin Blade. "Then let's kill them all." The will of the world: "No, you can't." It says this, then slaps her with a sickly debuff. Tanjiko: "..." One last question: Why does she have to work overtime without getting paid, only to be exploited by her boss? Later, Tanjiko resolves the remaining threats, exhausted and nearly worked to death, only to turn around and see Senior Muzan being held down and forced to bask in the sun. Tanjiko: "I am literally falling apart!" Later still, she discovers the threats aren't completely dead. They've broken through the world's barriers, and all sorts of strange things have slipped in... Some guy with ringed eyes: "Let the world know pain..." Tanjiko punches him flying. "Screw making the world feel pain. The world's boss is already falling apart!" Some one of the Twelve Demon Gods: "If you want peace and prosperity, sacrifice your eldest son to me..." Yoriichi draws his blade. "Screw sacrificing him. I'm the one who has to kill my older brother!" Some fake King Solomon: "I will burn human history to ash..." Muzan rushes over, looking excited. "Then burn me first!" Tanjiko and Yoriichi: "...?" Is there a traitor among us? Tanjiko = Tanjirou + genderbend + going dark Don't ask why a genderbent Tanjirou is called Tanjiko. Don't you think Tanjiko sounds nice too? The will of the world is even worse than the trash boss. The cover features Demon King Tanjiko. A story from the "Muzan is a good guy" series. Some important characters have personal headcanons. Read with caution. The Savior Trio's personalities change drastically. Later on, you may see: a merciless, dark Tanjiko; a friendly Muzan who wants to die; and an irritable Yoriichi who wants to kill his older brother. Theme: Face the person you used to be.