They Loved Her First: Various Yandere Demon Slayer X Hybrid Reader

Muzan had killed a family and what he found was the woman left behind a three month year old baby. Muzan picked her up and the the moment the baby babbled at him, smiling at him his world changed. This little human had him wrapped around her finger. He would raise her, and protect her, but once she ran away he would mourn her. Once she came back into his life, he was obsessed with her, seeing her as the woman she was. HIS Woman. He loved her first and so did the upper moons. She belongs to them, not those damn Hashiras!

(WARNING: They were not into you when you were a child, they only became romantically interested in you when you came back and they realized you were a demon hybrid. NO CHILD ATTRACTION, All characters are aged up to adults, this will go back and forth in chapters from past to adult hood and flashbacks!)