The 'Silence of the Lambs' by Thomas Harris is also a dark mysterious novel. The main character, Clarice Starling, has to deal with the brilliant but extremely dangerous and mysterious Hannibal Lecter. The serial killer plot and the mind games between Clarice and Lecter make it a really engaging and dark read.
Dark mysterious stories usually involve elements of the unknown. It could be a strange place, like an old, abandoned mansion in a story that gives off an eerie feeling. Or it could be an unknown entity, such as a shadowy figure that haunts the characters but has no clear origin.
There's the mystery of the Dyatlov Pass incident. A group of hikers died under very strange conditions in the Ural Mountains. Their tent was cut open from the inside, and they were found scattered around the area, some with strange injuries. To this day, the exact cause of their deaths remains a mystery.
There could be a story where the dark crystal ball has some sort of power over the dragon. Maybe it was used to control the dragon in an ancient time, and the dragon was forced to do evil deeds under its influence.
A mysterious organization that lived in the dark was often called the Dark Organization or the Evil Organization. This organization may be a fictional entity or a real one, but it is usually a dark, evil, illegal organization dedicated to achieving its goals.
I would suggest 'Black Hole' by Charles Burns. It's set in a strange suburban world that has been affected by a sexually transmitted disease that causes strange mutations. The art style is dark and the whole mood of the graphic novel is very mysterious as the characters deal with their changing bodies and the secrets that come with the epidemic.
The art style can make a graphic novel strange, dark and mysterious. For example, if it uses a lot of dark colors like black, deep purples, and grays, it can set a dark mood. Also, if the characters are not typical but rather have odd features or behaviors. Strange creatures or abnormal events in the story contribute to the mystery.
Another one is 'The Yellow Wallpaper'. A woman is confined to a room with yellow wallpaper for her 'nervous condition'. As time passes, she starts to see strange things in the wallpaper and descends into madness. It's a mysterious look into the mental state of the protagonist and the oppression she faces.
In a Slender Man and little girl fanfic, the story could be told from the perspective of the little girl. She might notice strange things around her town, like people disappearing. Then she realizes that Slender Man is behind it all. She could be a brave character, trying to warn others and fight against this terrifying entity. It could also show how the town reacts to her warnings, some believing her and some thinking she's just a scared child making things up.
One aspect of 'Dark Side of the Moon' Supernatural fanfiction could be exploring the afterlife in a more in - depth way. Writers might create scenarios where the characters face their inner demons or unresolved issues in this strange realm. For example, Dean and Sam could encounter versions of their past selves that force them to re - evaluate their choices.