The concept of survival is also big. The underworld is a dangerous place, and characters have to find ways to stay alive. This could involve making deals with unsavory characters or using their wits. Redemption is sometimes a theme as well. Some characters try to break free from the dark path they're on and seek atonement.
Isolation is a theme that pops up often. The underworld is a place that is often shunned by the rest of society, so characters can feel very alone. They might be the only ones of their kind or they might be ostracized for their actions. This sense of isolation can drive their actions and decisions within the story.
One of the main themes is identity. When characters from different universes crossover in underworld fanfiction, they have to re - evaluate who they are in relation to the new characters and situations. Survival is also a big theme. Since these are often dangerous worlds, characters have to find ways to stay alive in the face of new threats. And there's the theme of discovery. Characters discover new abilities, new species, and new cultures when they cross into different underworlds. For instance, an Underworld vampire might discover a new way of using their powers when in the world of another vampire - related series. This theme of discovery adds an element of excitement and mystery to the fanfiction.
One common theme is the exploration of a new world. The underworld in Naruto fanfiction is often a mysterious and dangerous place. So, Naruto has to explore it, learn its secrets, and find his place. Redemption can also be a theme. Sometimes Naruto tries to redeem characters from the underworld or even the underworld as a whole. And of course, friendship. He makes new friends in the underworld, which is different from his Konoha friends, and these relationships help him in his adventures.
One common theme is the power struggle. In both Twilight and Underworld, there are different factions with their own powers. Fanfictions often explore how these powers interact and who comes out on top. Another theme is love across boundaries. Just like in the original works, fanfics also deal with the idea of characters from different groups falling in love, such as a vampire and a human in Twilight or a vampire and a lycan in Underworld.
Many Harry Potter underworld fanfiction also have a theme of redemption. A character who has been involved in the underworld may try to find a way to break free from it and redeem themselves. It adds an interesting layer of depth to the story, showing that not all who are in the underworld are completely lost.
One common theme is the clash of different vampire cultures. Bella is from the Twilight vampire world which has its own set of rules, and the Underworld has a very different take on vampires. So, stories often explore how these two different vampire cultures interact when Bella is somehow thrown into the Underworld. Another theme could be power struggles. In the Underworld, there are constant battles for power among different factions, and Bella's presence can either disrupt or become a part of these power dynamics.
A common theme is the relationship between Selene and the OC. It could be a friendship, a mentorship, or even a romantic relationship. For example, the OC might be a new vampire that Selene takes under her wing.
One common theme is power struggle. Since both Twilight and Underworld have different power hierarchies among their supernatural beings, crossovers often explore how these hierarchies clash or merge when the two worlds meet.
One of the main themes is survival. The underworld is a dangerous place, and the male oc has to use his wits and skills to stay alive. There's also the theme of identity. He might be trying to figure out who he really is in this dark world. And secrecy, as he has to keep his true intentions and actions hidden from his enemies.
In 'Dark Hermione and Dark Bellatrix fanfiction', a common theme is the transformation of character. Hermione, who is typically seen as a good and studious witch, undergoes a significant change to become darker. Bellatrix, on the other hand, may also have her own form of transformation as she interacts with this new, different Hermione. Another important theme is the exploration of the wizarding world's underbelly. These fanfictions often take readers into the parts of the wizarding world that are not so well - known, filled with dark magic and dangerous secrets. It's an exciting way to see the familiar world of Harry Potter from a completely different perspective.
Another common theme is loyalty. You'll see characters having to decide where their loyalties lie, whether it's to their family in the underworld, their friends, or to a particular cause. For example, in many fanfics, a character might have to choose between loyalty to a cruel boss and doing what's right. And this creates a lot of internal and external conflict.