It might include a vampire hunter who is on Jeremy's trail. Also, Jeremy's family members could be important characters as he tries to protect them from the vampire world he has now become a part of.
Well, in 'jeremy becomes a vampire fanfiction', perhaps Jeremy is turned into a vampire by a mysterious vampire who has some special plan for him. As a vampire, he discovers new powers and abilities. He might get involved in a vampire society full of politics and rivalries. He has to learn the rules of this new world and figure out if he wants to be a 'good' vampire or not.
Perhaps a plot where Jeremy uses his new vampire powers to protect Mystic Falls. He becomes a sort of vampire - hero. He could use his enhanced speed and strength to fight off other supernatural threats that the town faces, all while trying to come to terms with the fact that he's no longer human.
At first, Elena might be shocked and a bit scared when she finds out. Their relationship could become strained as she has to adjust to the idea of her brother being a vampire. But over time, they could grow closer as Jeremy learns to control his vampire side and Elena sees that he's still the same person deep down.
One great 'Vampire Diaries Jeremy Fanfiction' is 'Jeremy's New Path'. It explores Jeremy's journey after he discovers new powers. It's really engaging as it shows his struggle to control these powers and how it affects his relationships with the other characters in the show.
One great Damon and Jeremy fanfiction is 'The Bond Beyond Blood'. It delves into how Jeremy, after his experiences in Mystic Falls, starts to see Damon in a new light. Their relationship evolves from one of distrust to a sort of begrudging respect and then to an unexpected friendship. The story is full of action and the typical Vampire Diaries drama.
Another interesting pairing could be Jeremy and Caroline. Caroline is already a vampire, so she could mentor Jeremy in a way. They could have a fun, flirty relationship where they go on adventures together and learn more about the vampire world as a team. It would be interesting to see how their personalities clash and mesh at the same time.
One interesting story could be about Jeremy exploring his new vampire powers in a way that the show didn't fully explore. For example, he might use his vampire abilities to protect the town from a new threat that's not related to the typical vampires or werewolves. Maybe he teams up with some unexpected characters to fight this new danger.
Archive of Our Own (AO3) is also a good option. It has a more diverse range of fanfiction, including some really unique takes on Jeremy's character. The tagging system on AO3 makes it easy to find exactly what you're looking for in terms of plot, genre, and relationship dynamics.
They are an interesting pairing because they are so different. Klaus is an old and powerful vampire with a dark past, while Jeremy is a young human (for a while) with his own set of problems. The contrast between their power levels and personalities makes for great storytelling.