Edward would definitely interact differently. If Bella goes back in time and changes her initial approach, Edward might be more or less intrigued by her. For example, if she's more confident, he might be even more drawn to her than in the original story.
Jacob would also have a different relationship with Bella. If Bella has a different timeline, Jacob might not be as resentful towards her relationship with Edward. He could be more of a friend to her from the start, and they might work together on things that Bella now knows about from going back in time.
Edward Cullen would likely be a main character. His reaction to Bella's situation, whether it's concern for her well - being or struggle with his vampiric instincts around her period blood, could be a major part of the story.
Caroline Forbes is another character. As a vampire herself in Mystic Falls, she could either befriend Bella or be jealous of her presence. Caroline is known for her strong personality and her relationships within the vampire community.
Alice Cullen can be a very popular character. Since she can see the future, in a 'reborn as bella swan' scenario, her interactions with Bella could be really different. Maybe she tries to guide Bella in a new way based on her visions. Also, Carlisle Cullen is popular. His father - figure role towards Bella might be explored further in these fanfictions.
One interesting plot could be that Bella goes back in time and tries to prevent certain events from the original story that led to pain or danger. For example, she might stop James from hunting her in the first place.
Lucius would probably be quite haughty at first. He's used to being in a position of power in the wizarding world. Bella, on the other hand, would be a bit defiant. But over time, Lucius might start to respect Bella's tenacity.
In fanfiction, they often interact with a mix of curiosity and attraction. Savitar, being a powerful speedster, is intrigued by Bella's unique human - turned - vampire qualities. He might show off his powers to her at first, like running in a blur around her to get her attention. Bella, on the other hand, is both fascinated and a bit intimidated by him. She may ask him a lot of questions about his powers and his world.
It could be a character named Jake. He's a very competitive Bakugan brawler who sees Bella as a threat because she's quickly rising in the ranks. He's always trying to one - up her in battles and spread rumors about her to make other brawlers not trust her.
Well, aside from the obvious ones like Alucard, Integra, and Seras, Bella might also interact with Walter. Walter is an old and experienced member of the Hellsing staff. He could be a mentor figure to Bella, teaching her about the history and secrets of the Hellsing Organization. Another character could be the Major from the Millennium Organization. If there's a crossover or a story where the two organizations clash, Bella would surely cross paths with him. His crazy and unpredictable nature would make for some interesting interactions with Bella.
Obviously, Bella Swan is one of the main characters. And the Creeper Mates, though it's not clear exactly who they are as individuals yet. They are likely to be a group or species that Bella interacts with in a significant way.
Obviously, Bella Swan is a main character. She is the one in the unwanted bride situation and the story likely revolves around her journey.