One idea could be a vampire Sith Lord. Imagine a character who combines the dark powers of the Sith from Star Wars with the immortality and blood - sucking nature of a vampire from Vampire Diaries. Another could be a Jedi using their powers to protect a town from vampires, like how they protect the galaxy in Star Wars.
A really interesting plot could be if the Force in Star Wars was somehow related to the magic in Vampire Diaries. Maybe a character discovers that they can use the Force to control vampires or that the magic in the Vampire Diaries world is a different manifestation of the Force. Also, a story where a vampire falls in love with a Star Wars character and has to choose between their vampiric nature and the new world of Star Wars would be engaging. There could be a lot of conflict as the vampire tries to adapt to a world without blood - sucking and deal with their eternal love.
One idea could be being reborn as a long - lost relative of one of the main characters. For example, a long - lost sister of Elena. This could stir up a whole new dynamic in the Mystic Falls gang. You could bring in new powers or a different perspective on the vampire - werewolf - witch drama.
One idea could be being reborn as a long - lost relative of the Salvatore brothers. Maybe you have some hidden power that was lost in the family history and now you have to navigate the vampire - filled world of Mystic Falls while trying to figure out your new abilities. Another plot could involve being reborn as a witch in the fanfiction world. You could use your magic to either help or hinder the vampires and other supernatural beings in town. You might also be reborn as a human with a special gift of seeing the future, which would put you in a dangerous position as everyone in the Vampire Diaries world would want to use your power for their own ends.
One idea could be a story where Elena discovers a long - lost relative who is also a powerful vampire hunter. This relative tries to turn Elena against her vampire friends, creating a lot of internal conflict for her.
One plot idea could be a black cat that is actually a shapeshifter. In the world of Vampire Diaries, it could be a witch who was cursed to take the form of a cat. The cat could befriend Elena and help her in her battles against the vampires. Maybe it has some special powers like being able to sense danger from afar. Another idea is that the black cat is a familiar to an ancient vampire. This vampire uses the cat to spy on the other characters. The cat could also be a key to unlocking a hidden mystery in Mystic Falls, like a secret passage or a long - forgotten spell.
One idea could be a new student who is a powerful witch arriving at the high school and getting caught in the middle of the vampire - werewolf feud. Another could be a time - travel plot where a character goes back to the early days of the high school when the original vampire drama began. Maybe a story about a human student who discovers a secret society within the high school that is dedicated to studying the vampires and trying to find a way to co - exist with them.
Well, perhaps Hermione is sent to the 'Vampire Diaries' world to retrieve a powerful magical artifact that has somehow ended up there. Along the way, she meets Damon and Stefan. She forms an unlikely friendship with them as they help her search for the artifact. In return, she uses her magic to protect them from some of the more dangerous supernatural threats in their world.
One idea could be that Enzo and Caroline team up to solve a mystery in Mystic Falls that's related to an ancient vampire curse. They might discover that their combined powers are the key to breaking it.
Maybe a demigod gets turned into a vampire in a strange magical accident. This would create a whole new set of challenges as they try to balance their demigod powers with their new vampire nature. They might have to deal with the vampire politics in Mystic Falls while also trying to stay true to their Olympian heritage. It could lead to some really interesting character development and power struggles.
One idea could be that some of the Glee characters visit Mystic Falls for a singing competition. While there, they get caught up in the vampire drama. Maybe a vampire takes a liking to Rachel's voice and wants to turn her into a vampire so she can sing forever. Another plot could involve the vampires using the Glee club as a cover to hunt during their events.
A plot idea might involve Jeremy and Tyler getting trapped in an alternate dimension. In this dimension, they have to rely on each other completely to survive. They face strange creatures and challenges that force them to use their unique skills. As they struggle to find a way back home, they also learn more about each other's pasts and form a deeper bond.