Demon Lord's Secret Wife

Kuro, a jaded otaku, awakens not as a hero, but as Muzan Kibutsuji, the progenitor of demons. Cursed with immense power and an insatiable hunger, he's trapped in the body of humanity's greatest foe. But Kuro harbors a secret that would shatter both demon and slayer alike: he is secretly married to Shinobu Kocho, the Insect Hashira, a woman whose every waking moment is dedicated to exterminating his kind. Their clandestine marriage, born from a desperate pact made in a forgotten past, forces Kuro to navigate a treacherous double life. He must maintain his terrifying facade as the Demon Lord while secretly protecting the very humanity he's sworn to destroy, all while Shinobu hunts his brethren with a smile masking her own agonizing secret. Their love is a fragile ember in a world ablaze with hatred, threatening to consume them both.