One idea could be that Harry has an alternate identity as a Muggle detective. He uses his magical skills secretly to solve cases that have a magical element but are disguised in the Muggle world. For example, he might be investigating a series of strange disappearances that are actually the work of a dark wizard trying to gather ingredients for a powerful spell.
Another idea is that Harry has an alternate identity as a famous Quidditch star from a far - off land. He pretends to be this star to infiltrate a group of dark wizards who are using Quidditch events to smuggle illegal magical items. He has to keep up the charade while also trying to stop their evil plans.
One interesting idea could be that Harry decides not to defeat Voldemort in a traditional battle. Instead, he uses a powerful spell of love and redemption to turn Voldemort back to his original self, Tom Riddle, a lost and confused boy. This would completely change the whole dark - vs - light dynamic of the story.
One idea could be that in the alternate dimension, Dementors are actually friendly creatures that help protect Hogwarts instead of causing fear. They could use their powers to keep dark wizards at bay in a different way.
One idea could be that in the alternate dimension, Voldemort won the war long ago. Hogwarts is now a dark and dreary place, with Death Eaters as teachers. Harry and his friends, who are part of an underground resistance, have to find a way to travel back in time to change the course of history.
In these fanfics, the theme of adaptation is quite common. Harry has to adapt to his new identity, whether it's a new name, a new magical ability, or a new social standing. Another theme is the exploration of different magical cultures. If his identity is changed in a way that he's associated with a different group, like a foreign wizarding community, it delves into different magical practices. And identity crisis is also a key theme. Harry may struggle with who he is now compared to who he was supposed to be in the original story.
One idea could be that in this alternate universe, Hufflepuff is the dominant house in Hogwarts. They have a secret society within the house that holds the key to an ancient magic that can save the wizarding world from a new, unknown threat. And the main character, a Hufflepuff student, discovers this by accident and has to take on the responsibility to gather the members of the society.
One interesting idea could be that Harry decides not to destroy the Horcruxes but instead finds a way to redeem Voldemort. Maybe he discovers some long - lost magic that can purify the dark parts of Voldemort's soul. Another idea might be that Hermione becomes the true hero who finally defeats Voldemort with her vast knowledge of magic and out - of - the - box thinking. And there could also be a scenario where Ron sacrifices himself in a completely unexpected way to save Harry and the wizarding world, leading to a bittersweet ending.
In 'harry potter alternate school fanfiction', there are often ideas like a school that is floating in the air. This school could have its own set of rules and traditions. For example, students might have to use flying brooms to get from one class to another. Also, some fanfics might explore a school that is hidden deep underground. It could be a place where students study ancient and lost magics that have been forgotten by the wizarding world above. There could also be an alternate school where the students are sorted by their magical abilities rather than their personalities as in Hogwarts.
In some 'Harry Potter alternate sorting ceremony fanfiction', there could be ideas like the Sorting Hat considering different qualities. For example, it might focus more on a student's creativity rather than just the traditional Gryffindor courage, Ravenclaw wisdom, Hufflepuff loyalty, and Slytherin ambition. Maybe a character who is very artistic gets sorted into a new, made - up house based on that creativity.
One interesting plot could be if Harry was sorted into Slytherin instead of Gryffindor. It would completely change his relationships and how he's perceived. He might have to deal with the prejudices of his own house while also trying to figure out his role in the fight against Voldemort.
One idea could be that in the alternate dimension, Voldemort won the war and Hogwarts is now a dark and dreary place where students are taught only dark magic. Another could be that the wizarding world is merged with the Muggle world in a strange way, like there are magical creatures running amok in London streets. Or perhaps in this alternate dimension, Harry was sorted into Slytherin and has to deal with a whole different set of challenges and prejudices.