Well, clearly Elena and Klaus are the main characters. Elena is often portrayed as a strong - willed and compassionate human (or vampire depending on the plot of the fanfiction). Klaus, on the other hand, is the complex and powerful original vampire.
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.
Another possible plot is that Elena, while initially afraid of Klaus, starts to learn about his complex personality through a series of encounters. As a result, she begins to question her own beliefs about good and evil in the vampire world, and this creates a lot of tension and character development within the fanfiction.
There could be a fanfic where Elena is in danger from a group of werewolves. Klaus, having his own reasons for not wanting Elena to die, steps in. He uses his cunning and strength to fend off the werewolves. This could lead to a change in their relationship, with Elena starting to see Klaus in a different light, perhaps as more than just an enemy.
Well, it can have a huge impact. For instance, if Klaus saves Elena from a life - threatening situation, Elena might start to feel a sense of gratitude towards him. This could make her more open to his presence and less hostile. It could be the start of a strange friendship or an even more complex relationship where she's conflicted between her loyalty to her friends and this new - found connection with Klaus.
Well, a possible plot is that Elena's pregnancy is the result of a spell gone wrong. Klaus, despite his initial shock, decides to stand by her. This could lead to a series of events where they have to fight off those who see the baby as a threat. It could also explore how Elena deals with the physical and emotional changes of pregnancy while being in a rather strange relationship with Klaus. And the baby might have some unique abilities that are both a blessing and a curse.
One great Klaus and Elena fanfic could be 'The Unlikely Bond'. It delves into how they might form an unexpected connection beyond the usual vampire - doppelganger dynamic. It has a really interesting plot where they team up to face a common enemy that threatens both their worlds.
You can start by looking on fanfiction.net. It has a large collection of Klaus and Elena fanfics. Just use the search bar and type in 'Klaus and Elena' and you'll get a bunch of results.
One popular 'Elena Saves Klaus' fanfiction is 'A Different Kind of Bond'. It explores a unique relationship between Elena and Klaus as she decides to save him from a dangerous situation. The story delves into their complex emotions and the consequences of her actions.