Well, it could be that Tom Riddle's father is in a difficult situation when they meet. Maybe he's ill or in some sort of trouble. Tom, instead of showing any compassion, sees this as a sign of weakness. His father, on seeing Tom, feels a sense of guilt for leaving him. Tom starts to question his father about his past, his family, and his reasons for abandoning him. As the conversation progresses, Tom's father tries to make amends, but Tom, already on the path of becoming Voldemort, scoffs at the idea and leaves his father, with his father realizing too late the monster his son has become.
In a 'Tom Riddle meets his father' fanfiction, perhaps Tom uses magic to track down his father. When they meet, his father is a normal, non - magical man living an ordinary life. Tom, with his air of superiority, tries to manipulate his father into doing his bidding. But his father resists, not understanding the power Tom holds. This struggle between them could lead to a series of events where Tom's true nature is revealed to those around his father, and Tom has to decide whether to kill his father to keep his secrets or try to use him in some other way.
Tom's character could become more vengeful. Meeting his father, who may have abandoned him, could make him more determined to prove his worth and power. He might see his father as a symbol of all those who have wronged him, and this could lead to a more rapid descent into darkness.
In a 'Harry Potter meets Tom Riddle' fanfiction, a really unique plot could be that Tom Riddle is reborn as a normal wizard without the dark desires due to some powerful magic. Harry Potter meets this new Tom and they become friends at Hogwarts. However, there are still some remnants of the old Tom's power that attract dark forces. So, Harry and Tom have to work together to fend off these threats while also exploring Tom's new identity and how it affects the future of the wizarding world. This would involve a lot of character development for both Harry and Tom, as they navigate their relationship in this new scenario.
Yes, there are some out there. Some fanfictions in this concept can be really interesting as they completely flip the established relationship in the original 'Harry Potter' lore. They might explore how Harry's character traits would be different as a father figure to Tom Riddle, and how that could have changed the whole course of events in the wizarding world.
One common theme is redemption. The idea that Harry could be Tom's father might lead to a path of redemption for Tom Riddle. Another theme could be alternate history. Since this is a big change to the original story, it often explores how different the wizarding world would be.
If Tom Riddle was Hermione's father in fanfiction, it would completely change Hermione's backstory. She would likely have a very different upbringing, perhaps in a more complex family situation. Her magical abilities could be even more powerful and unique. The story might explore how she discovers her true parentage and how she deals with the stigma of being related to the most feared dark wizard. It could also lead to a whole new set of adventures as she tries to prevent the dark path that her father took or tries to redeem his name.
They might be curious about it. Since Tom Riddle is such a big part of Harry's past, his kids would probably want to know more. But it could also be a bit of a burden, like they feel they have to live up to something or prove they're not like Tom Riddle.
You could also create a fanfiction where a new character, an orphan just like Tom, arrives at the orphanage. This new character could either be a positive influence on Tom, trying to show him kindness and friendship, or they could be in competition with him for the limited resources or attention in the orphanage. This would add a new dynamic to the story of Tom Riddle in the orphanage.
One possible plot twist could be that Tom Riddle's dark tendencies start to resurface despite Hermione's positive influence. Maybe he begins to secretly manipulate those around him at Hogwarts while still maintaining a facade of being a reformed child. This could lead to a rift between Hermione and some of her friends who suspect Tom but don't understand why Hermione is so trusting.
One possible plot could be Hermione discovering the truth about her godfather being Tom Riddle and struggling with her own identity. She might be torn between her loyalty to her friends and the new - found family connection.
One possible plot could be that Tom Riddle, using his charm and manipulation skills, lures Ginny into a secluded place under false pretenses and then takes her captive. He might be after some information that he believes Ginny has, perhaps related to the secrets of Hogwarts or the Weasley family. Ginny, being a brave character, would constantly try to resist and find a way to escape while Tom Riddle would be using his dark magic to keep her in check.