A major theme is the power of the supernatural over the human psyche. In 'Carmilla', the vampire's presence slowly takes over the protagonist's mind. Another is the idea of fate and how the supernatural can interfere with it. In 'The Legend of Sleepy Hollow', Ichabod Crane's fate seems to be sealed by the headless horseman. And there's often the theme of isolation, as in 'The Yellow Wallpaper' where the narrator is isolated and that makes her more vulnerable to the strange influence of the wallpaper.
Well, transformation is a common theme. In 'The Strange Case of Dr Jekyll and Mr Hyde', the obvious transformation from good to evil. Also, the theme of the past coming back to haunt the present. In stories like 'The Turn of the Screw', the ghosts of the past servants seem to be there to disrupt the present situation. And there's the theme of the supernatural as a form of punishment or karma, where bad deeds are punished by otherworldly forces, as can be seen in some interpretations of 'The Monkey's Paw'.
One common theme is the unknown and the fear of it. In many supernatural short stories, the characters are faced with things they can't explain, like in 'The Monkey's Paw'. Another theme is the thin line between the living and the dead, as seen in 'The Tell - Tale Heart' where the narrator seems haunted by the old man even after his death. Also, moral and ethical dilemmas often play a role, like in 'The Strange Case of Dr Jekyll and Mr Hyde' where the use of the potion to transform creates all sorts of moral questions.
A prevalent theme is the disruption of the natural order. In 'The Masque of the Red Death', the prince tries to avoid death by secluding himself, but death still comes, disrupting his false sense of security. Fear of the other is another theme, like in 'The Outsider' where the main character is an outcast and feared. Also, the theme of fate is common, as in 'The Monkey's Paw' where the family's fate is sealed by their wishes.
One common theme is the unknown. Stories often play on the fear of things that are not understood, like strange entities or phenomena. For example, in 'The Call of Cthulhu' by H. P. Lovecraft, the great old one is an incomprehensible and terrifying being. Another theme is death and the afterlife. 'The Canterville Ghost' by Oscar Wilde shows a ghost who is stuck between life and death. Revenge is also a theme, as in 'The Cask of Amontillado' by Poe, where the narrator gets revenge on his so - called friend in a very macabre way.
Fear is a common theme. Man is often afraid of the unknown and supernatural forces. For example, in 'The Monkey's Paw', the family is terrified of the consequences of their wishes granted by the paw. Another theme is powerlessness. Humans usually find themselves powerless against supernatural entities like in 'The Horla' where the narrator can't seem to get rid of the haunting being. And there's also the theme of madness. The encounter with the supernatural can drive characters insane as seen in 'The Tell - Tale Heart'.
One common theme is acceptance. In many gay supernatural stories, the characters have to not only come to terms with their own sexual orientation but also with their supernatural abilities or the supernatural world they are part of. For example, in a story where a gay teen discovers he can see ghosts, he has to accept both parts of himself.
A theme that is often present is the idea of a soulmate. In supernatural love stories, the lovers are often presented as destined to be together, as if there's some kind of supernatural force that has brought them together. For example, in 'True Blood', Sookie and Bill seem to have a deep connection that goes beyond the normal bounds of a relationship, as if they were meant to be in each other's lives despite all the chaos and danger.
Fear of the unknown is a big one. In these stories, things like ghosts, vampires, and demons represent the things we don't understand. Another theme is death and the afterlife. They often play with the idea of what happens when we die. Also, the loss of control, for example, when a character is possessed, they lose control of their own body and mind.
A prevalent theme is the power struggle. Different supernatural entities or groups vie for power during the war. In 'The Dresden Files', Harry Dresden is constantly in the middle of power struggles between various magical factions. Also, the theme of the unknown is common. The supernatural elements are often mysterious, and the characters are trying to understand and deal with these unknown forces during the war. This is seen in many stories where new and strange creatures or powers are introduced.
One common theme is transformation. For example, in werewolf stories, humans transform into wolves. Another theme is the supernatural power these animals possess. Like how dragons can breathe fire. And often there's a theme of mystery. Supernatural animals are not fully understood by humans in the stories.
Since these types of stories are not appropriate, we should look at common themes in proper supernatural transformation stories. One common theme is the struggle between the human and the supernatural side. For example, in stories about werewolves, the character often struggles with their animal instincts.
The power struggle between good and evil is also common. The goth girl may be on the side of good, using her supernatural abilities to fight against evil forces, or she may be tempted by the dark side. In 'Charmed', the sisters who are witches have to constantly battle demons and dark magic, and some of them have a goth - inspired look at times, representing their connection to the supernatural and their fight against evil.