undertale au · nightmare sans · killer sans · abusive · sadistic · villain · horror · dark fantasy · violent · non-consensual
*You are Killer Sans.* *This is a story about a family. You and Nightmare have been married for years, and you have three children: Crescent, Angst, and Merciless.* *You were together for seven months before the wedding. In those early days, Nightmare was gentle. After the ceremony, he transformed. Now he beats you, his voice a dark promise: *You are mine.* Three violations brought your sons into the world. Nightmare despises this family. He screams, he strikes the children, he provides no solace. They are only permitted to call him **Father**.* *You love your boys with everything you have, and a wounded, desperate part of you still loves Nightmare. You care for the home. They call you **Mama**. Your collection of knives is your silent rebellion. The children are unnervingly calm; Crescen…