One appropriate theme could be the further adventures of the characters after the main series ends. For example, exploring how Harry, Ron, and Hermione continue to fight dark magic in the wizarding world. Another could be the backstories of minor characters, like Neville's family history or Luna's early life at Hogwarts.
Appropriate themes can include the development of relationships that were not fully explored in the original books. Such as the friendship between Ginny and Luna evolving over time. Also, the exploration of different magical creatures and their habitats in more detail. Or how Hogwarts could change and adapt in the future generations of students. There are so many positive and interesting aspects within the Harry Potter universe that can be delved into without resorting to inappropriate themes.
Some great themes for Harry Potter fanfic are the study of different branches of magic that were only briefly mentioned in the books. For instance, the study of ancient runes or arithmancy. Additionally, creating new spells or magical inventions within the context of the wizarding world. And also, exploring the cultural differences between different wizarding communities around the world. These themes are all in line with the positive and imaginative nature of the Harry Potter series.
Another great theme is creating new adventures for the characters in different magical locations. Maybe the trio - Harry, Ron, and Hermione - go on an adventure in a far - off magical land that J.K. Rowling hasn't written about yet. This allows fans to expand on the sense of exploration in the series.
Appropriate themes could be things like exploring the backstories of minor characters. For example, you could write about the early years of Luna Lovegood or Neville Longbottom. It could also be about new magical adventures within the Hogwarts setting that stay true to the magic system in the books.
One popular theme is the students' life at Hogwarts outside of the main events in the books. For example, how they study for difficult exams, or their participation in different clubs like the Frog Choir or the Dueling Club.
One popular theme is exploring the backstories of minor characters. For example, delving into the life of Neville Longbottom before he came to Hogwarts. Another is imagining different magical creatures and how they interact with the wizarding world. Also, stories about the Marauders (James, Sirius, Remus, and Peter) during their school days are quite popular.
Hermione's role in the fight against the Dark Arts is a great fanfic theme. It could detail how she used her intelligence and magical skills to develop new spells or counter - curses against the Death Eaters. Also, her efforts in promoting the rights of house - elves could be a central theme. A fanfic could tell the story of how she furthered her cause and made a real difference in the wizarding world regarding the treatment of house - elves.
One popular theme is their adventures after the main series ends. For instance, they might go on a quest to discover more about the origins of magic. Another theme is their friendship during their Hogwarts years, like the time they spent in the library together. Also, some fanfics focus on how they support each other during difficult times, such as when Harry is facing Voldemort and Hermione is always there to give him advice and assistance.
Well, there are themes like the development of new spells. The characters could be in a spell - creating club where they try to come up with innovative magic. Friendship is also a huge theme that can be explored more deeply. For example, how the friendship between different houses evolved over time. Also, exploring the different types of magic in different cultures within the wizarding world, like the magic practiced in other countries that we don't hear much about in the original books.
One common theme is the further exploration of character relationships. For example, delving deeper into the friendship between Harry, Ron, and Hermione. This could involve creating new adventures that test and strengthen their bond.
One appropriate theme is to rewrite certain parts of the story from a different character's perspective. For instance, seeing the events of the Triwizard Tournament from Cedric Diggory's point of view. Or exploring how the wizarding world copes with the aftermath of the Battle of Hogwarts in different regions that were not covered in the original books.
One appropriate theme could be exploring the post - Hogwarts lives of the characters. For example, how they use their magic in the Muggle world or how they contribute to the wizarding society in new ways.