Yes, it can be. In the 'Harry Potter' universe, there's a lot of room for creative exploration in fanfiction. The idea of Harry Potter having an influence on Tom Riddle, or in a sense 'raising' him in an alternate scenario, allows for interesting character development and plot twists. It can show how different Harry's influence could have changed Voldemort's path.
One idea could be that Fem Harry Potter, with her unique perspective from another time, tries to raise Tom Riddle with a sense of love and family that he lacked in his original upbringing. Maybe she uses her knowledge of the future to guide him away from the dark path. For example, she could introduce him to different magical cultures early on to broaden his view.
One idea could be that Harry discovers a time - traveling device and goes back to Tom Riddle's childhood. He decides to take Tom under his wing and raise him with love and kindness. As a result, Tom doesn't become Voldemort and instead uses his magical abilities for good.
At first, it would probably be very difficult. Tom is a complex character with a lot of pride. Harry, on the other hand, has a deep - seated hatred for Voldemort. But as Harry gets to know the young Tom, he might start to see him as a lost child. Their relationship could slowly shift from one of suspicion to a more paternal - like bond as Harry tries to mentor Tom.
One key theme could be redemption. Tom Riddle, who is known for his evil deeds as Voldemort, is now 'good' and raising Harry. This could explore the idea of whether someone with such a dark past can truly change and do good. Another theme might be the power of nurture. How does Tom Riddle's upbringing of Harry shape Harry's character? It could also touch on the theme of family, as this unusual relationship between Tom and Harry redefines what a family can be in the wizarding world.
The original plot would be drastically changed. In the original, Voldemort is Harry's archenemy. But here, with Tom Riddle being good and raising Harry, the whole dynamic of the 'chosen one' vs the dark lord is gone. Harry would grow up with a very different set of values and skills, probably learning magic in a more nuanced way from Tom. Also, the relationships with other characters like Hermione and Ron would be altered. They might not become friends in the same way, as Harry's upbringing would shape his personality and social interactions differently.
One great 'Harry Potter Tom Riddle Fanfiction' is 'The Heir of Slytherin's Redemption'. It shows a different side of Tom Riddle, exploring what could have happened if he had been given a chance at a different path. It has a really interesting plot that keeps you hooked from start to finish.
One popular idea in such fanfiction could be that Harry, through some magical time - turning or alternate reality scenario, discovers Tom Riddle before he fully becomes Voldemort. Harry might see the good in Tom that was lost over time and tries to prevent his fall to the dark side. Their soulmate connection could be a powerful force that draws them together, even as their destinies seem so opposed.
One great 'Harry Potter' Tom Riddle slash fanfiction is 'The Heir of Slytherin's Heart'. It delves deep into the complex relationship between Harry and Tom Riddle. The author does an amazing job of exploring their characters in a new light, with a plot that keeps you on the edge of your seat.
I'm not sure if it's popular. It's a rather niche and unusual concept, so it might not have a wide following. But in the world of fanfiction, there are always small groups of people interested in unique and out - of - the - ordinary ideas.