One interesting plot could be Bella developing a new power while living with the Cullens. For example, she might gain the ability to communicate with animals like some of the other vampires. This would add a new dynamic to her relationship with the Cullens and also pose new challenges and adventures as they try to keep it a secret from the outside world.
Perhaps a plot where they embark on a journey to discover the origin of their Futa existence within the Twilight universe. This could involve meeting ancient vampires or other supernatural beings who hold the key to their transformation. They would face many challenges and learn more about themselves along the way.
One interesting plot could be where Jacob and Bella go on a secret adventure in the forest together. They discover a hidden part of the forest that has a special meaning to the werewolves. It could involve them facing some small challenges like crossing a rapid stream or finding their way back when they get lost.
One interesting plot could be Bella having to teach vampire children about the human world in a way that they can understand without revealing too much. For example, she might tell them stories of holidays like Christmas, which are so different from their vampiric existence.
There could be a plot where Bella has a premonition about a danger that's going to befall the wolf pack. She then tries to convince them of the impending threat, but they are hesitant to believe her at first. Through her determination and the evidence she manages to gather, she eventually gets the pack to take her seriously and they all work together to face the danger.
One interesting plot could be Bella's struggle to control her new vampire powers. She might face difficulties in adjusting to her heightened senses, like being overwhelmed by the smell of blood. Another plot could involve her relationship with Edward. Since she's now a vampire, their dynamic might change, and they could face new challenges together.
In some of these fanfictions, one plot could be that Bella's kidnapping is part of a scheme by a new vampire coven that wants to use her as bait to lure Edward. They might think that by having Bella, they can draw out Edward and his family and then overpower them to take over their territory.
In some fanfictions, Bella might develop a special friendship with Zafrina. Zafrina could teach Bella some of her unique skills, like enhancing her mental shielding in a different way. This could lead to Bella having a new level of power and confidence that she didn't have before in the original story.
A really cool plot could be that they turn into humans and then try to blend into high school as normal students. They have to deal with typical high - school drama like fitting in, making friends, and dealing with bullies, all while hiding their true identities from everyone around them.
Bella is obviously one of the most popular. Since she is the main character in the original series, in fanfiction she often remains the central focus. Her relationships with the Cullens, especially Edward, are often explored in great depth.
It depends on how you define 'popular'. There are a lot of Twilight fanfictions out there, and this particular theme might not be the most common. However, within certain subsets of the fanfiction community, it could be quite popular. For example, fans who are interested in exploring power dynamics and the darker side of the characters might be drawn to this type of fanfiction. It also might appeal to those who want to see Bella in a more vulnerable position and how she would react to being bullied by the Cullens, which is a departure from the typical story where she is often the center of their affections.