A more complex plot might be where both Harry and Tom are sent back in time to a point where the Hogwarts founders are still alive. They get involved in the founding events of Hogwarts, and Harry has to stop Tom from influencing the founders in a way that would make Hogwarts more exclusive and dark - sided. Harry could try to work with the founders to see the potential danger in Tom even at a young age.
One idea could be that fem Harry travels back in time and tries to prevent Tom from becoming Voldemort. Maybe she uses her knowledge of the future to show him a different path, like introducing him to the concept of love and friendship earlier. Another plot could involve them traveling to different time periods together and having to solve mysteries related to magic in those eras.
A possible plot is that a young wizard, who is a huge fan of Harry Potter stories in his own time, somehow gets transported back to Tom Riddle's era. He initially just wants to see the famous Hogwarts of that time. But then he crosses paths with Tom Riddle. He decides to use his knowledge of the future to try and befriend Riddle and change his path. However, he soon realizes that Riddle is far more complex and dangerous than he expected, and his actions start to have unforeseen consequences on the future.
One idea could be that Harry accidentally travels back in time and meets a young Tom Riddle before he fully turns evil. He tries to change Tom's path by befriending him and showing him kindness, which leads to a series of events where the future of the wizarding world starts to change in unexpected ways.
Well, perhaps in the fanfiction, Hermione time - travels to Tom Riddle's era and she attempts to understand his early life better. She could try to find the root of his evil and change it. For example, she might discover that a particular event in his childhood was the turning point. As for Tom Riddle traveling to Hermione's time, he could be fascinated by the advanced magic and the different social structure in the wizarding world, which might make him question his own beliefs.
Perhaps Ginny and Tom both travel to a different time period, like the Middle Ages. There, they have to work together to survive in a world full of magic they don't fully understand yet. Ginny could use her modern knowledge of magic, while Tom's natural cunning helps them navigate the social and political aspects of that time. This could lead to a strange alliance and a re - evaluation of their relationship.
Perhaps they travel back to a time in Hogwarts' history. Harry could interact with his parents as a student, and Narcissa could see a different side of the school. They might end up changing the way certain relationships develop. For instance, Harry could influence his father to be less of a bully, which in turn could have a huge impact on the future friendships and enmities at Hogwarts.
Another plot idea is that Harry Peverell time - travels to different points in his own family's history. He gets to meet his ancestors, learn about their secrets and magic, and discovers that his family has a much larger role in the wizarding world's history than he ever thought. He could then use this knowledge to better understand his own place in the wizarding world and his connection to the Deathly Hallows.
They could time - travel to a time in Hogwarts' history when a great mystery was unsolved. Harry and Teddy could work together to figure out what really happened. For example, they might explore the mystery of the Chamber of Secrets long before Harry's own encounter with it. Teddy's inquisitive nature and Harry's experience could lead them to some amazing discoveries.
One idea could be that Harry and Fleur travel back to the time of the founders of Hogwarts. They could witness the creation of the houses and perhaps even influence some of the early magical traditions. For example, they might help Gryffindor and Slytherin better understand each other, which could have a huge impact on the future of Hogwarts and the wizarding world.
A possible plot for Harry and Tom mate fanfiction is that they are both sent on a special mission by Dumbledore. Along the way, they have to rely on each other's strengths. Tom might use his intelligence and cunning, while Harry uses his courage and loyalty. They could also encounter magical creatures that they have to work together to defeat. This would force them to put aside their differences and form a bond. And as they complete the mission, they realize that they can learn a lot from each other.