Well, in the fanfiction world, if Klaus turns Elena into a vampire, she would probably have a whole new set of challenges. Firstly, she'd have to deal with her new bloodlust. Elena, being a very empathetic person, might struggle a great deal with the urge to feed on humans. Also, her relationships with her friends would change drastically. Her human friends like Bonnie and Caroline might be a bit wary of her at first. And her relationship with Damon and Stefan would also be on a different level. Damon might see her as a more equal partner in the vampire world, while Stefan might worry about her losing her humanity.
The story changes a lot. For one, Elena's place in the supernatural world shifts. She goes from being a target of vampires to being one of them. This means she's now part of the 'in - crowd' in a way. Her daily routine would be completely different. Instead of going to school during the day, she'd be prowling at night. And her relationships with the other characters would be redefined. Stefan and Damon would have to see her in a new light, and she might start to have a different understanding of Klaus too, not just as a threat but as someone who has given her a new kind of life.
There are fanfictions where Elena and Klaus are thrown into an alternate universe. In this universe, they are the only two vampires left and have to figure out how to survive and repopulate the vampire race. This forces them to work together closely and, over time, they develop feelings for each other that are far from the hatred they initially had in the original Vampire Diaries storyline.
One idea could be that Klaus, after being away for a long time, returns to Mystic Falls and finds Elena in a difficult situation. He decides to help her out of a sense of an old, unspoken connection. As they spend time together, they start to understand each other better and a relationship begins to form.
Sure. A lot of fans have written great fanfictions about Elena and Klaus' love. Some focus on the forbidden aspect of their relationship, like how Elena is supposed to be with the Salvatore brothers but has this unexpected connection with Klaus. It adds a new layer of drama and romance to the Vampire Diaries world.
Well, a prevalent theme is the idea of fate and how they are drawn to each other despite all the odds. Also, the theme of secrecy and the forbidden love aspect is quite common. Since Elena is part of the Mystic Falls gang and Klaus is an enemy in many ways, hiding their relationship from others is often explored in these fanfictions. And of course, there's the theme of sacrifice, where either Elena or Klaus has to sacrifice something for their love.
Another plot could involve Elena's transformation causing a rift in her relationship with Stefan or Damon. As a vampire, she may have different desires and values, which could create tension and drama. There could be a love triangle aspect where she is drawn to a new vampire character while still having feelings for the Salvatore brothers.
It could be an old vampire who sees Elena as a threat to his power or territory. Maybe he doesn't like the idea of a newly - turned vampire causing a stir in the vampire community and decides to take her out.
The consequences could be complex. On one hand, they might grow closer as they face the challenges of Elena's new existence. But on the other hand, Elena might struggle with her new identity and blame Stefan for turning her. This could create tension and strain in their relationship.
One great Klaus and Elena fanfiction is 'The Bond Beyond Blood'. It explores a unique relationship between them where they have to team up against a common enemy. The story is filled with intense emotions and some great character development for both of them.