Another plotline could be about the power struggle among fallen vampires. Maybe some want to rise again to their former status, while others are content with their new, more subdued existence. This can lead to a lot of in - group drama and conflicts.
There could also be a plotline where a fallen vampire falls in love with a human. This would be filled with challenges as the vampire has to deal with their own nature and the fact that they are 'fallen'. The human may also face difficulties in accepting the vampire's past and present situation.
Well, one common plotline is the exploration of different relationships that were not fully developed in the show. For example, some fanfictions focus on a deeper bond between Caroline and Bonnie. Another is the 'what if' scenarios, like what if Elena had chosen Damon right from the start? There are also fanfictions that introduce new supernatural elements to Mystic Falls, making the town even more dangerous and exciting.
Perhaps there's a plotline where the main character in 'Oblivion' has to deal with a forgotten prophecy that ties into the Vampire Diaries' lore. This could involve them trying to figure out what it means and how it affects their relationships with other characters like the Salvatore brothers.
Another plotline could be Jeremy learning more about Damon's past. This can lead to Jeremy having a better understanding of why Damon is the way he is. In one fanfic I read, Jeremy discovers some secrets from Damon's early days as a vampire and it changes their dynamic completely. Jeremy becomes more empathetic towards Damon and they form a stronger bond.
One interesting plotline could be Finn trying to protect Caroline from the darker elements of the vampire world. Since Finn has a more noble side compared to some other vampires in the show. Another could be a love story where they are star - crossed lovers, with the complications of Caroline's relationships with other characters in the Vampire Diaries universe. For example, Finn might have to compete with Stefan or Damon for Caroline's affection.
One interesting plotline is Nora's exploration of her magical abilities. In some fanfictions, she discovers new powers that she didn't know she had before. For example, in 'Nora's Magical Discovery', she can suddenly control time on a small scale.
One plotline that stands out is when Hayley gets caught in a time - loop and Klaus has to figure out how to save her. It's a really unique take on their relationship as Klaus has to relive certain moments over and over again, each time getting closer to understanding Hayley more deeply. Also, there are fanfictions where Klaus loses his memory and Hayley has to help him regain it while also protecting him from his enemies. This creates a lot of emotional and action - packed scenes.
One interesting plotline is when Klaus and Caroline are forced to work together to save a small town from a powerful dark magic in some fanfictions. It shows how their different powers and personalities can combine for a greater good. Another is when they travel to different realms to find a cure for a strange vampire illness. This allows for a lot of exploration and discovery.
One possible plotline could be that Damon is tortured by a powerful witch as revenge for something he did in the past. Maybe he accidentally killed a member of the witch's coven. Another could be that he is tortured by a group of vampires who want to send a message to Stefan. They might use vervain and sunlight to torture him in creative ways.
Perhaps a plot where Bonnie has to perform a powerful spell on Kol for some reason, like to remove a curse that is slowly killing him. During the process, they end up sharing memories and emotions, which makes them understand each other on a deeper level. This newfound connection then changes the dynamic of their relationship and they become closer, all while dealing with the consequences of the spell and the reactions of their friends.
Some fanfictions have a plot where Klaus and Caroline are in a parallel universe. In this universe, they are different people but still feel an inexplicable pull towards each other. There are also those where Caroline is turned into a hybrid like Klaus and they have to deal with the new challenges together. And then there's the plot where they are in a battle against a common enemy that is more powerful than any they've faced before, and their relationship is put to the ultimate test.