Another theme might be self - discovery. Bella might learn more about herself through her relationships with the three mates. She could discover what she truly wants in a partner and in life in general. The story could show her growth as a character as she deals with these complex relationships.
A theme of sacrifice could also be present. Maybe there are situations where either Bella or Amun has to sacrifice something for the sake of their relationship or for the greater good of the world they exist in. This could add depth and drama to the fanfiction story.
I'm not sure specifically which 'bella has three mates fanfiction' you're referring to. There could be many fanfictions with such a premise. Generally, it might involve a character named Bella having three romantic partners in a fictional story. It could explore complex relationships, different character dynamics, and how she manages her feelings for all three.
One possible theme could be friendship. Even though they are mates, a strong foundation of friendship is often important. They might rely on their friendship to get through difficult times. Another theme could be loyalty. They would be loyal to each other no matter what challenges come their way. It could also have a theme of discovery, as they discover new things about themselves and each other as their relationship progresses.
One common theme is loyalty. The three mates are often extremely loyal to Harry and vice versa. They stand by each other through thick and thin, whether it's against dark wizards or school bullies.
Perhaps one of the mates is a fellow student at Bella's school. He could be a smart and kind human boy. And the other mate could be an otherworldly being, like a faerie with magical powers. This would create a really interesting dynamic as Bella tries to navigate relationships with such different individuals.
Another plot could be that they are on opposite sides of a conflict initially. But as they realize they are mates, they have to find a way to reconcile their differences and work together. This could involve a lot of internal struggle for both of them as they deal with loyalty to their respective sides and their new - found bond.
One possibility could be that Bella is in a world where having multiple mates is common. She might struggle to balance her feelings for both mates. Maybe one mate is more adventurous and the other is more nurturing, and she has to figure out how to incorporate both relationships into her life.
One of the mates could be a mysterious and brooding vampire. He has a dark past but is drawn to Bella's innocence and kindness. The other mate might be a werewolf, strong and protective, who has known Bella for a long time and has always had a soft spot for her.
One possible plot twist could be that Bella discovers Caius has a hidden agenda all along, and it's not just about their relationship. Maybe he's using their bond to gain power within the vampire world. Another twist might be that Bella has a secret power that is awakened by her connection with Caius, and this power changes the dynamics of their relationship and the entire vampire community.
Perhaps there is an external threat to their mateship. A powerful villain could be trying to break them apart for some reason, like using magic or blackmail. So, they have to fight against this threat to stay together.