A short scary story for you. There was an old, abandoned house at the end of the street. A curious boy decided to explore it. As he entered, the door slammed shut behind him. He heard whispers all around him. He walked into a room and saw a rocking chair moving on its own. In the chair, there was a faint silhouette of an old woman. He tried to run but found himself lost in a maze of dark hallways.
Some fanfics might focus on the psychological aspects of the characters. For example, they could delve into why the characters react the way they do to the strange situations they're in. Maybe it's about their fear of change, or the way they've been indoctrinated by the 'lessons' they're being taught. The fanfic could also be a way to give the characters more agency, as in the original they often seem to be at the mercy of the surreal events.
There was a mirror in an old mansion. Whenever someone looked into it, they saw a face that wasn't their own. One girl, who was dared to look into it, saw a pale, sad face staring back at her. The face started to cry blood, and then the girl felt a cold hand on her shoulder. She turned around but saw nothing. When she looked back at the mirror, the face was gone, but she could still hear the sobbing.