Bella's personality would likely become more complex. Being part of the Mikaelson family means being involved in a lot of power plays and family politics. So, she'd probably become more guarded. Also, she might develop a bit of a darker side. The Mikaelsons have a long history of violence and betrayal, and she'd have to navigate that world. She may not be as trusting as she was in the Twilight world and would need to be more self - reliant.
Well, for starters, Bella would become more confident. In the Twilight world, she was often overshadowed by the vampires and werewolves around her. But as a Mikaelson sister, she'd be part of a powerful family. This newfound status would boost her self - esteem. She'd also become more adaptable. The Mikaelson family is constantly on the move and facing new challenges, so Bella would have to learn to roll with the punches. And her sense of loyalty would expand. Instead of just being loyal to a small group like in Twilight, she'd have to be loyal to her entire Mikaelson family, which could be a big adjustment for her.
She might become more assertive. In the Twilight series, Bella is often rather passive, but in the Mikaelson family, she would need to be more forceful to hold her own. She'd have to learn to be more cunning and strategic, like the Mikaelsons are.
If Kol's twin was in Bella's body, her personality would likely change the story a great deal. Kol's twin would probably be more assertive and less passive than Bella. She might not put up with Edward's over - protectiveness in the same way and would be more likely to go off on her own adventures. This could lead to her getting into more dangerous situations or uncovering secrets faster.
At first, their relationship might become strained. Bella's sister would have to keep her new identity a secret from Bella, which could create distance. But once Bella finds out, they could become closer as Bella tries to understand what her sister is going through. Bella might be more protective of her sister now that she's in a more dangerous world.
As a Mikaelson twin, Bella would likely become more assertive. In the Twilight series, Bella was often more passive, but in the Mikaelson world, she'd need to be tough. She'd have to learn to use her newfound powers quickly. Also, her relationships would change. Instead of being focused on Edward or Jacob, she'd be dealing with the complex family dynamics of the Mikaelsons. Her sense of loyalty would expand to include her new family, and she might become more calculating in her actions to protect them.
Klaus would probably be very intrigued by Bella. He's used to getting his way with most people, but Bella is not easily swayed. So he might start by trying to charm her, but she would be resistant. For example, he could offer her power or protection, but she would be more concerned about her own values and the people she cares about in Forks.
When it comes to the other Cullens, like Alice, Kol's sister could be both intrigued and a bit dismissive. Alice's visions might seem like a novelty to her at first, but then she could start to resent them if they interfere with her own plans. And with Jacob, she might be amused by his werewolf nature. She could see him as a more natural predator compared to the 'tame' vampires of the Cullens. Overall, her interactions would be a mix of curiosity, rivalry, and in some cases, friendship.
She would likely become more confident in her own strangeness. Instead of being the somewhat shy and self - deprecating Bella we know from the Twilight series, she would embrace her darker side. For example, she might not be as hesitant to stand up to those who try to bully or intimidate her.
With Edward, their relationship would be different. They'd be more equal in terms of strength and power. No longer would Edward need to constantly protect Bella. Instead, they could fight side by side against their enemies. Their relationship might also have a new dynamic of competition, as they both explore their new vampiric abilities.
Her relationship with Edward would definitely change. Edward is used to a more innocent and reserved Bella. If she becomes a Katherine Pierce fan, she might become more assertive and independent, which could either make Edward more attracted to her in a new way or cause him to be wary. He might not like the new, more dangerous side of Bella that is emerging.
One idea could be a story where Bella discovers the world of the Mikaelsons after being turned into a vampire. She crosses paths with Elijah and they form an unlikely alliance to deal with a common threat in the supernatural world. They learn from each other's experiences, with Bella's knowledge of the Volturi and Elijah's centuries - old wisdom.
She might become more protective. As Silas's sister, she would have a natural inclination to safeguard him, which could make her more assertive.