In the 'damon is bella's father fanfiction', it could start with Damon having a strange feeling that he has a connection to someone. As he investigates, he finds out about Bella. Their relationship could be filled with misunderstandings at first. For example, Bella might be resentful that he wasn't there for her growing up. But over time, they could learn to understand each other. Damon could introduce Bella to his world, whether it's a world of magic or some other extraordinary place, and they could form a strong bond.
Well, it could be about Damon having to protect Bella from the various threats in their supernatural world. Maybe she has some unique powers that draw unwanted attention.
There could be Bella's mother. She would be an important character as she was part of the relationship that led to Bella's birth. Maybe she has some secrets or reasons for keeping Damon away from Bella all these years.
Well, one possibility is that Bella's presence completely changes the dynamic between Stefan and Damon. Maybe she's the mediator in their constant feuds. Since she's their sister, she might have a special power that could either help or hinder them in their vampire world. For example, she could have a unique ability to sense danger that the brothers don't have, which would make her an important asset in their battles against other supernatural beings.
Well, it could be that Damon, using his vampire speed and strength, appears just in time to stop Victoria from attacking Bella. Maybe he's been secretly watching Bella because he senses she's in danger from the vengeful Victoria. He then fights Victoria off, and Bella is both terrified and grateful.
The plot could involve Bella being in a vulnerable situation, like being lured by James into a trap. Damon, having some connection or interest in Bella, senses the danger. He then uses his skills and knowledge of the supernatural world to confront James. Damon might have to face not only James' physical attacks but also some sort of dark magic or trickery that James has up his sleeve. But in the end, Damon prevails and saves Bella, and this event could be the start of a new relationship or alliance between Damon and Bella, or it could just be a heroic one - time rescue.
The plot could involve Caius hiding his true identity from Bella for a long time. She might grow up thinking she has a normal father, until strange things start to happen. For example, she notices that her father never ages. Then, when she discovers the truth, she has to come to terms with being part vampire herself. Caius would then have to protect her from those who might want to harm her because of her unique heritage.
One possible reason could be that Bella has a certain allure or mystery that Damon finds more captivating than Elena. Maybe Bella represents a new and different kind of challenge for him.
Caroline could be in the story. She might be Bella's friend or a rival. If she's a friend, she could help Bella navigate the supernatural world. If a rival, it could be because of her relationship with Damon or Stefan in some way. Also, Klaus could be a character. He might see Bella as a means to get to Damon, or he could be interested in her unique abilities if she has any.
Damon could be a vampire or some other powerful supernatural being. Bella might be a human, perhaps with some special quality that makes her a target for James. Maybe she has a unique scent or power that she's not even aware of yet.
One idea could be that Damon and Bella meet in a casino in Vegas. Damon, with his charm, tries to win Bella over in a game of poker. Another could be they both get involved in a mystery related to an old Vegas hotel, and they have to work together to solve it.