Often, other vampire clans that oppose Bella's transformation can be the main antagonists. They might see her as a threat to the vampire world order. For example, a traditionalist clan that believes humans should not be turned so easily could try to harm Bella or drive her away from Edward.
One common theme is the exploration of their eternal bond. Since they are vampire mates, their connection is supposed to last forever, and many fanfictions focus on how they maintain and strengthen this bond. Another theme is the challenges they face due to their different natures. Bella was once human, and becoming a vampire brings a whole new set of issues. Also, the theme of protecting each other and their family is quite common. They are mates, so they will do anything to keep each other safe.
Another common theme is the struggle between the vampire and human worlds. There are often conflicts arising from the differences in their natures, values, and lifestyles. Fanfiction writers usually show how Edward and Bella deal with these differences and try to find a balance between the two worlds.
It's the forbidden love aspect. In many of these fanfictions, there are rules in the vampire world that make their relationship not so straightforward. Their love has to overcome these obstacles, like the fact that Edward could potentially harm Bella. This adds a lot of drama and tension to their relationship, which readers find exciting. Also, their deep emotional connection, which is often portrayed very intensely in the fanfictions, makes it really appealing.
Well, they would become even closer as they are about to be parents. Edward would be extremely protective of Bella, not just because she's his love but also because she's carrying their child.
In some fanfictions, Edward leaves Bella because he's cursed. He doesn't want Bella to be affected by the curse. Bella, being in love with him, tries to find a way to break the curse. She travels far and wide, meets different supernatural beings, and in the process, she also becomes more powerful. When she finally finds a way to break the curse, Edward realizes how much she truly loves him.
Well, a common plotline is Bella's discovery of new vampire senses. In fanfiction, it could be that she discovers she has a unique sense that other vampires don't have, like being able to sense the emotions of humans from a great distance. Also, there could be a plot where Bella has to hide her new vampire self from her human family and friends, which creates a lot of tense and emotional moments as she tries to keep her double life a secret.
One popular fanfiction could be where Edward and Bella travel to different vampire clans around the world, facing various challenges together. It might explore their relationship in new and exciting settings.
There's a fanfiction called 'Left Behind'. Here, Edward leaves Bella thinking he's losing his humanity and becoming a danger to her. Bella refuses to accept this and tries to bring him back to his senses. She delves deep into the history of vampires and their emotions to find a solution. It has a very emotional and engaging plot.
One popular 'Edward and Bella vampire mates fanfiction' is 'A Different Fate'. It explores an alternate universe where Bella has different powers and she and Edward face new challenges together. Another great one could be 'Eternal Bond' which delves deeper into their vampire relationship, showing how they navigate the vampire world as mates in a more detailed way. There's also 'Twilight Redefined' that gives a fresh take on their story with some interesting twists to their relationship.