A possible plot for this fanfiction could be traveling through the different dimensions of the Harry Potter universe. There might be a dimension where Voldemort won, and seeing the desolate and dark state of the wizarding world there. Another aspect could be traveling with a group of friends to explore the magical ley lines of the world. These ley lines could be the source of powerful magic and hold secrets waiting to be uncovered. And, a journey to the magical libraries around the world, like the restricted section of the Hogwarts library on a grand scale, seeking rare and dangerous books of magic.
One idea could be exploring what would happen if Harry Potter used his magic to create a parallel Hogwarts where students from different magical cultures around the world come together. This could lead to new friendships, rivalries, and the discovery of new spells and magical abilities unique to each culture.
One idea could be being reborn as a muggle - born wizard who has a unique ability to communicate with magical creatures in ways others can't. This could lead to all sorts of adventures in the Forbidden Forest and uncovering secrets about the creatures that help in the fight against Voldemort.
One idea could be that Harry discovers a new and ancient magic that is the key to defeating a previously unknown dark force. For example, he might find a hidden spell in a long - forgotten book in the Room of Requirement.
Maybe in this fanfiction, Harry discovers a new kind of magic that allows him to reshape the wizarding world's laws across the globe. He could make Hogwarts - style education available everywhere, even in the remotest Muggle villages. This would not only spread magic knowledge but also bring the two worlds closer together.
Another idea is a story where a spell goes wrong during a Defence Against the Dark Arts class. Instead of just a minor mishap, it creates a portal to an alternate dimension where Hogwarts has a completely different layout and the magic there works in strange ways. The students then have to find their way back while dealing with the strange new magical threats in that dimension.
One idea could be exploring the wizarding world in a different time period, like the Middle Ages. Wizards could have different magical practices and face different threats. Another could be a story where Harry's children discover a hidden part of Hogwarts that has been locked away for centuries, filled with ancient magic. Maybe also a fanfiction where the roles are reversed, and the Death Eaters are the ones in power, and a group of young witches and wizards rise up against them in a new and unique way.
One idea could be a character going back in time to prevent a major dark wizard event that was overlooked in the original series. For example, they might try to stop the initial rise of Voldemort before he became so powerful.
Well, perhaps Harry travels back in time to the very beginning of the wizarding world. He discovers secrets about magic that have been long forgotten. He then uses this knowledge to make the wizarding world more inclusive and less divided by blood purity. Or he could time - travel during his own time period, like going back to his first year at Hogwarts over and over again to change small things that have big consequences in the future, like making sure Neville is more confident from the start.
Another plot could be that they travel back to the time when the Chamber of Secrets was first opened. Ginny, having been possessed by Tom Riddle in her own time, could use her knowledge to stop the young Voldemort from causing so much harm. Harry could also help by using his skills and knowledge of magic from his own time to combat the basilisk and keep students safe.
Well, a plot could be that a character from the future, like a descendant of Harry Potter, travels back in time to the time of the Triwizard Tournament. This character could have some knowledge of future threats and tries to prevent certain events during the tournament that could lead to greater disasters in the future. They might try to stop Voldemort's minions from using the tournament as a cover to carry out their evil plans. They could also try to make sure that Cedric Diggory doesn't die, which would have a huge impact on the wizarding community as he was a very popular and promising young wizard.