There's a fanfic called 'After the Battle' that delves into the rebuilding of the wizarding world after Voldemort's defeat. It explores how different characters adjust to the new peace and the changes in relationships among them. For example, Hermione's role in reforming the Ministry's educational policies. It's really fascinating as it gives a more in - depth look at the post - war wizarding society.
One interesting idea could be exploring the post - war wizarding world in more depth. How the characters deal with the aftermath of the great battle, like rebuilding Hogwarts. Another is delving into the relationships that were hinted at but not fully explored in the original series, such as Neville and Luna's friendship evolving into something more. Also, fanfictions might show new magical creatures or spells that were not in the original books.
There are 'Harry Potter fanfic fanfic' that focus on time - travel scenarios. Imagine if a character from the later books travels back in time to the first year at Hogwarts. This can create a lot of interesting plot twists as they try to change or preserve the original story line. Also, some fanfic fanfic might center around magical creatures in a way that wasn't fully explored in the original books, like the life of a hippogriff in more detail.
Some 'Harry Potter and Lily Potter fanfic' might focus on alternate universes. In one such story, Lily could have survived Voldemort's attack. She would then have to raise Harry in a world that is still recovering from the Dark Lord's first rise. This would change a lot of the dynamics in the story. Harry would grow up with his mother's love and protection, and Lily would have to deal with the knowledge that Voldemort could return at any time.
I'm not really in favor of the 'slaves' concept in fanfic as it can be a bit disturbing and against the positive spirit of the original 'Harry Potter' series. However, some fanfics might explore power dynamics in a more metaphorical way. But overall, the official 'Harry Potter' works focus on friendship, courage and magic, not slavery themes.
One interesting 'Harry Potter breed fanfic' story could be about the breeding of Hippogriffs in a more domesticated setting. Maybe it explores how wizards are trying to train them for various tasks like mail delivery in a different way than using owls.
One interesting 'Harry Potter Siren Fanfic' could be about a siren who uses her charm to influence the events at Hogwarts in a subtle way. Maybe she befriends Harry and tries to guide him through some challenges using her siren - like powers, which are different from magic but still effective.
There might be a fanfic where a MACUSA auror teams up with a Hogwarts student. They could be working together to stop a dark wizard who is causing chaos in both the American and British wizarding worlds. The story could explore how their different magical educations and approaches to magic come into play.
One interesting 'Harry Potter glutton fanfic' could be about Harry discovering a magical kitchen that creates endless amounts of his favorite wizarding treats. He goes on a bit of a food - filled adventure, trying all sorts of new and old magical delicacies.
There could be a 'Harry Potter betrothed fanfic' where Harry is betrothed to a new character created by the author. This new character might be from a different magical family. The story could then revolve around Harry learning about this new family's traditions and trying to blend them with his own life at Hogwarts.
Well, in many Harry Potter fanfics about the girls, Hermione is often depicted in various new adventures. For example, she might go on a solo mission to discover a long - lost magic spell. Another could be Ginny's story where she becomes a leading figure in a new Quidditch league.