One common theme is sisterly love and loyalty. These stories often show the twins supporting each other through thick and thin. For example, in many fanfictions, when one sister is in trouble, the other will go to great lengths to help.
A common trope is the twin having a different supernatural ability. For example, she might be able to control the elements while Bella has her mind - shield. Another is the love triangle, but instead of Edward - Jacob - Bella, it's between different characters involving the twin. Often, the twin also has a secret she's keeping from Bella which drives the plot.
One common theme is the bond between siblings. Since they are twins, their connection is often portrayed as very strong, and they rely on each other in different situations.
One common theme is sisterly bond. The fanfictions usually explore the deep connection between the twin sisters, how they support each other through tough times. Another theme is self - discovery. The sisters often embark on a journey to find out who they really are.
In these fanfictions, the theme of self - discovery is quite common. Bella and Kol, as twins, are on a journey to discover more about themselves through their new - found connection. Another common theme is the clash of two different worlds. Bella is from the Twilight world and Kol from the Vampire Diaries world, so there's often a lot of exploration of how these two worlds interact and collide when they come together as twins. There's also the theme of acceptance, both of each other and of their new family situation.
One common theme is family discovery. Since they are twins, there's a lot about uncovering their shared past and family secrets. Another theme is identity. They often have to figure out how being twins changes who they are in the context of the story.
A common theme is the power of sisterhood. The stories often show how Bella and her wolf sister support each other through tough times.
One common theme is family loyalty. The sister often stands by Bella through all the strange events in Forks. Another theme is self - discovery. As the sister witnesses Bella's experiences, she also starts to learn more about herself.
Another common theme is the discovery of self - identity. The older sister, while protecting Bella, also discovers more about herself. She might find out that she has some hidden powers or abilities. And in the process of dealing with all the Twilight - related events, she learns more about who she really is and what her role is in this strange world.
One common theme is identity. Bella has to re - define who she is as Caius' sister instead of just being Edward's love interest. Another theme is family loyalty. She has to figure out where her loyalties lie between the Cullens and the Volturi.
One common theme is identity. The twin sister often has to figure out who she is in relation to Jacob and the werewolf world. Another theme is family. How her relationship with Jacob and their family affects her actions.