Reincarnated As Muzan Kibutsuji

A college student died and got reincarnated into the world of a manga he once loved. Not as the main protagonist or as a side character, but as the antagonist? Would he be able to change his future?

𝕋𝕒𝕟𝕛𝕚𝕣𝕠 𝕏 𝔻𝕖𝕞𝕠𝕟 𝔽𝕖𝕞ℝ𝕖𝕒𝕕𝕖𝕣

Y/n is from the Sengoku era and was reborn to the Taisho era were tanjiro is now. Y/n was abandoned by her own parents and left her to starve in the cold. Then someone came along and it's was a strong demon Slayer that took her in. It was the one and only Yoriichi tsugikuni he didn't want to leave a child to starve i...