One interesting plotline could be Bella discovers Edward's vampire nature in a more dramatic way than in the original. For example, she might witness him using his super speed to save her from an immediate danger like a speeding car. Another could be that Edward is initially more hesitant to be around Bella because he fears his vampire instincts more strongly, creating more tension in their relationship.
Edward is often well - written. Fanfiction authors can delve deeper into his internal struggle with his vampire nature and his love for Bella. They can show more of his vampire abilities and how he uses them to protect Bella. Bella too can be very well - written. Authors might give her more agency and make her less of a damsel in distress, showing her strength in the face of the vampire world.
You could make their relationship more unique by having them communicate in a different way. For example, instead of just talking, they can have a mental connection from the start that only they can understand. This would make their bond more special and exclusive.
One interesting aspect could be how their relationship dynamics change. In the original, Edward was the vampire and Bella was the human, so reversing their roles might lead to a different power dynamic. For example, Bella as a vampire would have more physical strength and speed, which could make her more protective of Edward. Also, Edward as a human might struggle with his mortality compared to Bella's immortality, creating new tensions and storylines in the fanfiction.
One great fanfiction could be where Edward and Bella's relationship is explored more deeply in a different vampire society setting. For example, they might be in a vampire clan that has unique rules about human - vampire relationships.
In such a fanfiction scenario, perhaps their relationship would take on a very different dynamic. Since it's 1918, the social and cultural context was vastly different from the original story's setting. They might face different challenges, like dealing with the aftermath of World War I. Maybe Edward, being a vampire, would have to be more discreet in a time when superstitions were high and any odd behavior could draw unwanted attention.
One idea could be that Bella already has some latent vampire powers herself when she meets Edward. Maybe she can sense other vampires from a distance. This would add a new dynamic to their relationship as they both figure out what it means.
Bella might initially be terrified. She is a human being kidnapped by a vampire, after all. She could struggle and try to escape, using her wits and any available resources. However, since she has feelings for Edward in the original story, part of her might also be conflicted, wondering if there is a good reason behind his actions.
One common theme is the exploration of their love in different situations. For example, in some fanfictions, they face new threats to their relationship, like a new vampire clan that doesn't approve of their union. Another theme is the power dynamics between them. Since Edward is a vampire with special abilities and Bella is a human (at least initially), how they navigate that power difference is often explored.
Another good one is 'The Vampire's Mate'. It delves deeper into the vampire lore and how Bella, as a human, fits into their world. The relationship between Edward and Bella is portrayed in a more intense and detailed way, which makes for a very engaging read.