It is adapted from the playlist of Seven Deadly Sins. When I listened to it, I thought, "Oh, it would be great if it could be turned into a novel." So I started this trap. Because the writing is not good, I apologize if I can't express that feeling. Since it's an adaptation of a song, I don't know if it's considered fan fiction.
In short, the text is "Seven Deadly Sins of the V Family". It's a very nice song. Please be sure to listen to it.