One common theme might be the exploration of a unique relationship dynamic. Since Bella is feral, it could involve Jasper having to deal with her wilder nature in contrast to his more controlled self.
I'm not sure of a specific 'bella is feral jaspers mate fanfic' off the top of my head. You could try searching on popular fanfic websites like Archive of Our Own. They have a vast collection of fanfictions and you might be able to find what you're looking for there.
A key element is the relationship development between Bella and Jasper. It should show how they come to be mates, perhaps starting from an initial attraction or a shared experience within the Twilight - like setting.
There could also be an external threat that forces them to put aside their differences. For example, a new vampire or a group of enemies might attack their community. In this situation, Edward, Bella, and Jasper have to work together. During this time, Edward might realize that his jealousy is unfounded, and they all form a stronger bond as a result.
Yes, there are several. You can try searching on popular fanfic platforms like Archive of Our Own. Just type in the relevant keywords, and you'll likely find some interesting stories. However, the quality can vary, so it might take some time to find one that really suits your taste.
The idea of Bella being Carlisle's mate in a feral state is interesting because it's a departure from the normal relationship dynamics in the original story. It adds an element of the wild and unpredictable to their connection.
One great 'bella is jaspers mate' fanfic can be found on Fanfiction.net. It has a really interesting plot where Bella and Jasper's relationship develops in a unique way against the backdrop of the Twilight universe.
Well, he might try to distance himself from Bella at first. Maybe he'll avoid being around her and Jasper together, thinking it'll help him get over his jealousy.
A frequent theme would likely be the intensification of their romantic relationship. By Bella taking the lead in seducing Edward, it can lead to more passionate and perhaps more complex emotional interactions between them. Also, it might explore themes of power dynamics within their relationship, as Bella is usually the more vulnerable one in the original, but here she's in a more dominant position in terms of the seduction.
One common theme is the struggle against their different natures. Jasper has his violent past as a vampire, while Bella is a human. Fanfictions often explore how they deal with this difference.
Power is a common theme. Since Voldemort is a very powerful dark wizard and Bella is his devoted follower, their relationship in fanfiction often revolves around power sharing or Bella gaining power through her connection to Voldemort.