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.
In addition to Elena and Klaus, other characters from the Vampire Diaries universe might also be involved. For example, Damon or Stefan could play important roles in the fanfiction. They might try to interfere with Elena's interactions with Klaus, either to protect her or because of their own jealousies.
Another character that could be important is Elijah. He is often the voice of reason among the Originals. He might try to guide Kol in his relationship with Elena, or he could be against it if he thinks it will bring trouble to their family. So in this fanfiction, he could be a key figure in the development of the Kol - Elena relationship.
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.
Well, clearly Klaus and Caroline are the main characters. Klaus, the powerful and complex vampire, and Caroline, the spunky and determined vampire herself.
Well, Klaus is typically depicted as a powerful and mysterious figure. He has his own motives and desires which often collide with the human world. Caroline, on the other hand, is the one who brings out his more human side. She might be a student, or have some other normal human occupation that contrasts with Klaus' otherworldly existence. There may also be some supporting characters from the original story's universe who play roles in either helping or hindering their relationship.
The main characters are clearly Klaus and Future Hope.
The other vampires in Mystic Falls who are against the idea of a hybrid - vampire baby could be antagonists. They might see it as a threat to their way of life.
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.
A powerful witch coven might be the main antagonist. They could be jealous of the power that Klaus and Landon possess together. The witches might try to use dark magic to separate them and steal their powers for themselves. Maybe they have a prophecy that says the union of Landon and Klaus will bring about a change in the supernatural power balance that they don't want.
She could be terrified at first. After all, Klaus is a very powerful and dangerous vampire. But Elena is also a strong - willed character. So she might quickly gather her courage and start looking for ways to escape.
Klaus would likely become more complex. His tough exterior might soften as he anticipates fatherhood. He'd be more cautious and strategic to protect Elena and the unborn child. Elena, on the other hand, would grow from a somewhat naive girl to a strong woman. She'd have to face the harsh realities of being pregnant with a powerful vampire's child.