Often, other vampires or supernatural creatures could be the main antagonists. For example, vampires who are jealous of Damon's newfound mate might try to drive a wedge between them. Maybe there are some werewolves who see Bella as a threat to their territory because of her relationship with Damon.
In some fanfictions, there could be a powerful vampire coven that doesn't approve of the union between Bella and Damon. They might view Bella as a weak human who doesn't belong in their world and try to eliminate her. Or perhaps there is an ancient evil that is awakened by their bond and sees it as a threat to its own existence, so it sets out to destroy them both.
Sometimes, other werewolves who don't accept Bella as Jacob's mate could be the antagonists. They might think that a human - werewolf relationship goes against their pack's rules or beliefs.
Often, the Volturi can be antagonists. They have strict rules about vampire relationships and activities. If Bella and Jasper's relationship goes against their laws, the Volturi would oppose it. They might see it as a disruption to the vampire order they uphold.
Often, the Volturi can be antagonists. They might not approve of Jasper and Bella's relationship for some reason, like they think it goes against vampire laws or traditions. Another possible antagonist could be a rogue vampire who has a vendetta against the Cullens and sees Jasper and Bella's relationship as a way to get to them.
Perhaps there are demons or dark forces that are trying to disrupt the union between Bella and the God of War. These antagonists could be bent on causing chaos and destruction in their world, seeing their relationship as a symbol of hope that they want to destroy.
Yes, in many fanfictions, Bella is depicted as Damon Salvatore's mate. Fanfiction writers often create unique storylines where they pair characters in unexpected ways. This pairing can lead to interesting dynamics and plot developments.
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.
One common theme is the struggle for acceptance. Since Bella is the mate of both Damon and Stefan, there's often a plotline about how the vampire community or their friends accept this unusual relationship. For example, they might face judgment from other vampires who don't understand this triad.
One interesting plot could be the initial encounter between Bella and Damon. Maybe it's a chance meeting in a dark alley where Damon is immediately drawn to Bella's unique aura. Another could be their struggle to be together against the odds, like facing opposition from other supernatural beings in their world.
It could be the Titans who escaped from Tartarus and are seeking revenge. They might see Percy and Apollo's relationship as a threat to their plans of overthrowing the Olympians. Another possibility is some jealous gods or goddesses who don't like the idea of Percy and Apollo being mates.
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.