The main characters are Bonnie, a witch with great power and a kind heart deep down. Klaus, an Original vampire who is both feared and respected in the supernatural world. Their baby is also a main character, which is the focus of the fanfiction. There might also be other supporting characters like Damon and Stefan from the Vampire Diaries universe who could interact with Bonnie and Klaus regarding the baby. They might be curious, or they might be worried about the implications of this new addition to the supernatural world.
You can try searching on fanfiction websites like Archive of Our Own (AO3). It has a large collection of fanfictions from various fandoms, including ones related to Klaus and Bonnie. Just type in 'Klaus and Bonnie baby' in the search bar, and it should show you relevant stories.
Elijah could be on their side. He is Klaus' brother and might understand the importance of the baby, especially if he sees it as a way to keep Klaus in line or to bring about a new era of peace among the different supernatural species. He could use his diplomatic skills to protect the baby from threats.
One great Klaus and Bonnie baby fanfiction could be about how they deal with the challenges of raising a baby in a world full of supernatural threats. Maybe they have to protect the baby from other vampires or witches who might see the child as a threat or a valuable asset.
One interesting plot could be the baby having special powers due to its unique heritage. Since Bonnie is a powerful witch and Klaus is an Original vampire, their child might inherit a blend of magic and vampire abilities, like being able to use magic to enhance vampire speed or strength. Another plot could be the challenges they face in protecting the baby from the enemies they've made over the years. Enemies might see the baby as a threat or a valuable asset.
The baby could also have a special connection to the spirit world. Bonnie, with her witch powers, and Klaus, with his long and complex history, could find themselves on a journey to understand this connection. They might meet different spirits who either offer guidance or pose a danger to the baby as it grows up.
One possible plot could be that Klaus believes Bonnie has the key to a powerful spell that could help him gain ultimate power. So he kidnaps her. He whisks her away to a remote island. There, he tries to persuade her to help him, using both threats and false promises. He might start off being cruel but then gradually start to have some strange respect for her as she resists him.
A memorable moment in some fanfictions is when Bonnie first realizes that Klaus isn't just a one - dimensional villain. This realization often leads to a shift in their dynamic and makes for some really interesting character development.
There's 'Bonnie's Choice' where Bonnie has to make decisions that involve Klaus in a complex web of supernatural politics. It delves deep into her character and how she copes with Klaus's presence. This story is interesting as it shows a different side of their relationship compared to the show.