Demon Slayer: The Lost Ubuyashiki

As the Sengoku-Era was coming to an close, the previous leader of the Demon Slaying Corps thus the mantle of leadership had fell upon Kagaya Ubayashiki. As until one day, Muzan Kibutsuji had disguised himself as an human and made Amaya Ubayashiki fall pregnant then he revealed his manipulation, he left an warning "My off-spring shall be collected soon enough and your existence will expire" then for nine months she was pregnant until she gave birth to her daughter Nyx Kibutsuji however she knew her newly born daughter won't be safe from Muzan's clutches as she sent a basket containing her daughter and a scroll with her to explain the situation down the river, hoping that Kagaya would find it. Muzan Kibutsuji had swooped in and killed Amaya then he saw her memories, making off for Nyx as he successfully fetched her before Kagaya arrived and 18 years later, now that Nyx is 18 before the new year could arrive, she decides to make an break for it from the Infinity Castle coming in contact with the Hashira's from the Demon Slayer Corps as her new journey starts.