There are many Vampire Diaries fanfictions with this plot. One might find them on fanfiction.net or Archive of Our Own. Some fanfictions might have Stefan die heroically, like sacrificing himself to save his friends from a powerful enemy. Another possibility is that he could die as a result of a tragic accident or a curse that couldn't be broken.
Stefan Salvatore is one of the main characters in the Vampire Diaries novel. He is a vampire with a complex personality. He struggles with his vampire nature, often trying to resist his baser instincts. He is in love with Elena and his relationship with her is a central part of the story.
There are also fanfictions that focus on the power dynamics between them. As a vampire, Stefan has certain powers, and how that affects their relationship, whether it creates a sense of imbalance or a unique bond, is explored. For instance, Stefan's ability to protect Elena with his vampire strength can be a central plot point in some fanfictions.
Perhaps Stefan gets hurt in a race against time. He's trying to stop a spell from being cast that would endanger the whole town. But in the process, the caster of the spell manages to harm him. Elena would be desperate to save him, and she might turn to some of her own latent powers (if she has any in the fanfiction) to heal him. The Salvatores' relationship would also be put to the test as Damon blames himself for not being there to protect Stefan.
A fanfiction where Stefan gets hurt could start with him being lured into a trap by an old enemy. They manage to wound him badly using a weapon made of a special material that weakens vampires. Stefan would be in pain and his brothers and friends in the Vampire Diaries world would have to band together. Bonnie could use her magic to try and heal him while Damon plots revenge against those who hurt Stefan.
I really liked the fanfiction 'Stefan and Caroline: Unlikely Allies'. In this one, they start off as just friends trying to solve a mystery in Mystic Falls. But as they work together, their feelings start to change. It's interesting because it focuses a lot on their personalities and how they complement each other. There are some really good action scenes too, which makes it more exciting.
One popular fanfiction could be about Valerie and Stefan's secret meetings in the woods. Maybe they share a deep connection that was hidden from others in the series. They could be exploring their feelings for each other while also dealing with the chaos of the supernatural world around them.
The theme of 'power couple' is also quite common. Fans like to write about how Caroline and Stefan, with their combined strength, intelligence, and vampire abilities, can take on the various threats in Mystic Falls. They become a force to be reckoned with, and these stories usually have them saving the day in spectacular ways.
There's also 'Caroline's Choice'. This one shows Caroline having to make a difficult decision that involves Stefan. It's a more emotional piece, with great character development. It really makes you feel for both of them as they navigate through the complex situation.
One great fanfiction is 'Damon and Stefan: The Lost Bond'. It delves deep into their complex relationship, exploring their past and how it shapes their present actions in the show. It has some really interesting twists on their character development.