One common theme is the struggle with identity. Harry has to figure out who he is as a vampire in addition to being a wizard. Another theme is the isolation. Vampires are often solitary creatures, and Harry may experience this in these fanfics. Also, the power aspect is there. His new vampire powers and how he uses or misuses them.
One common theme is the exploration of power dynamics. Since Harry is submissive, it often shows how he interacts with more dominant vampire characters. Another theme could be identity. Harry has to figure out who he is now as a submissive vampire. And there's also the theme of relationships, like how he forms bonds with other vampires or characters from his previous life.
A common theme is the clash of different magical worlds. Since we have the world of Harry Potter which has its own set of rules and magic, and then we bring in Dahlia and vampires which have their own characteristics. Another theme is the struggle for acceptance. The vampire characters often have to deal with being different in a world that may not be very accepting of their nature, much like how some characters in Harry Potter face discrimination.
The themes can vary widely. Some fanfics might focus on the mystery aspect. For example, exploring the secrets of the vampire world that Severus inhabits and how Harry gets drawn into it. Another theme could be redemption. Maybe Severus, through his relationship with Harry, is seeking some form of redemption for his past actions in the 'Harry Potter' canon. There's also the theme of survival, as both characters may face threats due to Severus' vampire nature.
Well, in these fanfics, a major theme is the relationship between humans and vampires. Harry, being a human (or sometimes a half - vampire), has to navigate this complex relationship. There's also the theme of mystery. The vampire world in St Louis is full of secrets that Harry is constantly trying to uncover. Additionally, the theme of loyalty is often explored. Harry has to decide who to be loyal to, whether it's the vampire master or his human friends.
One common theme is the struggle between her human side and vampire side. For example, she might resist the urge to drink blood because of her human values. Another theme could be isolation. Since she is now different, she might feel alone even among her friends at Hogwarts.
One common theme is the struggle between the wizarding world and the vampire world. Since Harry is from the wizarding world and the OC is a vampire, there's often a clash of cultures and rules. Another theme is the idea of forbidden love. Vampires are often seen as outcasts in the wizarding world, so a relationship between Harry and a male vampire OC is usually frowned upon.
One common theme is the struggle with identity. When Naruto (or other characters) become vampires, they have to figure out who they are now. Are they still the same ninja? Another theme is the power struggle. Vampire abilities are often very powerful, so there's a conflict between using that power for good or being corrupted by it.
Friendship is also a common theme, which is very much in line with the MLP universe. Even in the presence of vampires, the fanfics often show how the characters try to maintain or build friendships. It could be a vampire making friends with ponies despite their differences, or ponies trying to befriend a vampire in order to save them from their vampiric ways. This theme of friendship often drives the plot forward and gives a positive message in these often - darker - themed fanfics.
Another theme is the search for identity. When a girl wants to be a vampire, she is often not satisfied with her current human self. In fanfics, she may feel like an outsider in the human world and believes that becoming a vampire will give her a new and more exciting identity. This can involve changing her appearance, her social status, and her relationships.
In many Chibi Vampire Anju fanfics, themes of friendship often play a big role. Since Anju is a unique character in the series, fanfic authors like to explore how she forms bonds with others. Also, the theme of her dealing with her vampire nature in a world that may not fully understand it is quite common. This can involve her trying to fit in, or having to hide her true self, which creates interesting storylines. Additionally, some fanfics might focus on her adventures in the supernatural world she inhabits, with all its unique creatures and settings.