Well, a common plotline is that they discover their mate bond in a rather unexpected way. For instance, in some fanfictions, there could be a magical event or a prophecy that reveals they are mates. Once they realize this, they have to deal with the complex emotions that come with it. Rosalie, who has always been protective of her family and had a certain image, might struggle with accepting her feelings for Bella. And Bella, who has been through so much with the Cullens already, now has to navigate this new relationship dynamic. It could also lead to some interesting power dynamics within the Cullen family as they adjust to Bella and Rosalie being mates.
One interesting plotline could be how they navigate their relationship in a world full of vampires and werewolves. For example, they might face challenges from the Cullen family who have different views on their relationship. Another could be their journey to understand and accept their unique bond as mates, which might involve them going on adventures together to discover more about their vampire nature.
In twilight Rosalie and Bella fanfiction, a great plotline could be Rosalie helping Bella adjust to her new vampire life in a more motherly way. Since Rosalie has been a vampire for a long time, she has a lot of knowledge and experience. Maybe she could help Bella with controlling her new powers and dealing with the emotional changes. There could also be a plot where they go on a journey together, away from the Cullen family for a while, to discover more about themselves and their place in the vampire world. This journey could bring them closer and make them see each other in a whole new light.
The main characters are obviously Bella and Rosalie. Bella, a human - turned - vampire, is known for her strong will and her complex relationship with the Cullen family. Rosalie, on the other hand, is a beautiful and somewhat aloof vampire with her own set of insecurities and desires. In these fanfictions, their relationship as mates takes center stage, and other characters from the Twilight series like Edward, Alice, and Carlisle may also play important supporting roles as they are part of the Cullen family and are affected by Bella and Rosalie's new relationship.
One possible storyline could be their adventures together in the vampire world. They might face challenges from other vampire clans and have to use their combined powers to overcome them.
One interesting plotline could be them bonding over a shared interest, like fashion. Rosalie's love for all things glamorous could rub off on Bella, and they could go on shopping sprees together. Another could be them facing a common enemy in the vampire world and having to rely on each other's unique strengths. For example, Bella's self - sacrifice nature and Rosalie's physical strength.
Another plot could involve Rosalie teaching Bella some of her more refined vampire skills, like how to move with extreme grace and elegance. This could lead to a deeper bond between them as Bella starts to understand Rosalie better. In the fanfiction, this newfound closeness might also stir some unexpected emotions among the other Cullens.
In some fanfics, male Bella might be a vampire hunter who initially targets Rosalie but then realizes she's not as bad as he thought. This creates a really interesting 'enemies to lovers' type of plotline.
Perhaps a plot where Jacob and Rosalie are forced to go on a journey together. During this journey, they face various challenges that test their limits. They might have to rely on each other's unique abilities to survive. For instance, Rosalie's super strength and speed could help in some situations, while Jacob's ability to transform into a wolf gives them an edge in others. Along the way, they develop a friendship that was unthinkable at the start.
One common plotline could be them facing challenges from other vampires who don't approve of their relationship. Since Emmett is strong and Bella has her own allure, others might see their union as a threat to the vampire hierarchy or social order.
One interesting plotline could be their adventures in the forest together. They might discover a hidden part of the forest that has some kind of magical or ancient significance. Another could be them dealing with the reactions of their respective families and friends to their relationship.