Loneliness and how to overcome it is a very common theme. Bella has to deal with being alone in these fanfictions, and it's about how she copes with that. Also, growth is a major theme. As she's alone, she can grow as a person, whether it's in terms of her confidence or her understanding of the world.
One common theme is friendship. Since they are part of the same family in the Twilight universe, fanfictions often explore how they support each other. Another theme could be adventure, like them going on a hunt together.
One common theme is the exploration of the supernatural world from their perspectives. Since they are from the vampire - related universe, many fanfictions delve deeper into the rules and mysteries of that world.
Another theme is the balance between work and personal life. In these fanfictions, Bella often has to juggle her duties as a police officer with her relationships, be it with her family, friends or love interests. For example, she might have to miss a family event because of an important police case.
One great 'Bella Swan Alone' fanfiction is 'Bella's Solitude Journey'. It delves deep into Bella's character when she's by herself, exploring her thoughts and emotions in a way that the original story didn't fully cover. Another is 'Alone but Strong Bella' which shows Bella growing independent and finding her own strength during her alone time.
One common theme could be Bella's interaction with Greek gods in the Twilight universe. For example, she might encounter Apollo and be drawn to his radiance, which could create a love triangle situation with Edward. Another theme could be her gaining powers from the Greek gods, like the power of prophecy from the Oracle at Delphi. It could also involve her being a reincarnation of a figure from Greek mythology, which then ties her to the gods in a more fated way.
One common theme is 'alternate universes'. Writers often explore what would happen if Bella made different choices or if the Twilight world had different rules. Another theme is 'power discovery'. Many fanfictions focus on Bella finding new powers or abilities she didn't have in the original story. 'Love triangles' are also common, where Bella may be caught between different characters in new and interesting ways.
One common theme is friendship. The OC often forms a unique bond with Bella, either helping her through tough times or just being a great friend. Another theme is the exploration of the supernatural world. Since the Twilight series has a lot of supernatural elements, the OC usually gets involved in that aspect too, like dealing with vampires and werewolves.
Often, a common theme is the alteration of the Twilight universe. Since Bella is now a god, she can change the rules, the setting, and the fates of the characters. There is also the theme of self - discovery. Bella has to figure out who she is in this new role, which is different from her human self. Additionally, themes of morality may come up as she decides how to use her god - like powers.
One common theme could be identity crisis. Bella is used to being a certain person in the Twilight world, but as a Lestrange, she has to reevaluate who she is. Another might be power struggles. The Lestranges are often associated with dark magic and power, so Bella could be caught in the middle of that. Also, family secrets are likely to be a theme as the Lestrange family has many secrets.
One common theme is the concern of others. For example, Edward and the Cullen family are usually very worried about Bella when she's sick. Another theme is Bella's own struggle, both physically and mentally. She might be worried about how her sickness affects her relationships or her future in the Twilight world.