One interesting plot could be Bella exploring her new vampire powers in more depth than in the original. For example, she discovers unique ways to use her speed and strength that no other vampire has thought of. Another plot might involve Edward and Bella facing a new threat to their family that is specific to their situation as a vampire - human - vampire family. It could be a new type of vampire with different abilities that challenges their way of life.
Some fanfictions may focus on the relationship between Edward and Bella after the events of Breaking Dawn. For instance, they might face difficulties in their marriage due to the differences in their vampiric natures. Maybe Bella is more adventurous now and wants to explore the vampire world, while Edward is more cautious. This could lead to some interesting relationship dynamics and character growth.
One interesting fanfiction could be about an alternate ending where Bella and Edward face a different kind of vampire threat in Breaking Dawn. It might show them using new powers or strategies to protect their family.
One interesting plot twist could be that Bella discovers a new power that is completely unexpected. For example, she might be able to control the elements in some fanfiction stories. This would add a whole new layer to her character and the story.
Edward and Bella are the top ones. Their love story has a huge fan base, and in fanfiction, writers often delve deeper into their characters. Jacob also remains popular. Even though his relationship with Bella has changed, his loyalty to her and his role in the werewolf pack make him an interesting character to write about. Also, the Cullen family members like Alice are popular as they add more depth and mystery to the stories with their special abilities.
Another idea is that they get involved in vampire politics more deeply. With their unique family situation and Bella's newfound abilities, they could become important figures in the vampire world. They might work towards changing some of the old vampire laws and traditions, especially those related to hybrids like Renesmee.
There are fanfictions that delve into Edward's perspective during the final battle in 'Breaking Dawn'. In these, he might be more conflicted about using his vampire powers to protect his family and Bella. He could be constantly thinking about the consequences of his actions and how it might affect their future together.
One great 'Breaking Dawn Edward Fanfiction' is 'Edward's New Perspective'. It delves deeper into Edward's thoughts during the events of Breaking Dawn, showing his internal struggles in a unique way. Another one could be 'Edward's Unseen Journeys' which explores his experiences away from Bella in that time period.
One interesting plot could be where Edward and Bella face a new supernatural threat together that tests their relationship in ways not shown in the original story. For example, a new type of vampire with unique powers arrives in Forks.
Another plot might involve an external threat to the royal family that Edward and Bella have to face together. Maybe a neighboring kingdom is planning an attack or there is a magical threat that only their combined powers (if they have any in the fanfiction) can overcome. This would test their relationship as they fight for the safety of their kingdom and each other.
Another plot could be that there's some sort of mystery or danger at the prom. Maybe a rival vampire group shows up, and Edward has to protect Bella while still trying to make their prom night special. They might have to dance and be romantic in between fending off attacks.
One interesting plot could be the child having special powers inherited from both Edward and Bella. For example, the child might have the ability to read minds like Edward and also possess Bella's strong will. Another plot could be the child's struggle to fit in with both the vampire and human worlds. Maybe they face challenges at school because they are different from the other kids.