Tom Riddle became Voldemort through a series of dark choices. He was born to a witch mother who died during childbirth. Growing up in an orphanage, he already showed signs of his dark nature. He discovered his magical abilities and became obsessed with power. His hatred towards muggles and his desire for immortality led him to split his soul multiple times, ultimately transforming into Voldemort.
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.
They can interact as students. For example, if they time - travel to when Tom Riddle was at Hogwarts, they could be in the same classes or clubs. Maybe they join the Duelling Club where Tom Riddle was known to participate. Another way is through chance encounters in the hallways or the library. They could strike up conversations about magic or Hogwarts history.
Tom Riddle might be very suspicious at first. He is a very intelligent and cautious person. He would likely view time travelers as a threat to his plans or as a strange new phenomenon that he wants to control. So, he could start by trying to figure out their motives and how they managed to travel through time.
Well, in some fanfictions, Tom Riddle could be developed as having a bit of a conscience from the start. Maybe the diary contains some part of his soul that wasn't fully corrupted yet. So instead of being purely evil, he has moments of hesitation or confusion about his actions.
At first, it might be rocky. Tom would be suspicious of Harry's intentions. But as Harry shows him genuine care, Tom would start to open up. Eventually, they could become like family, with Tom looking up to Harry as a role model.
Maybe it's a group of future Ministry of Magic officials who have become corrupted by power. They view Tom Riddle as an anomaly from the past and fear that his knowledge of old magic could disrupt their control over the wizarding world, so they become the main antagonists in his journey.
One unique way is through a shared secret. For example, Fem Harry discovers a hidden part of Hogwarts that is related to a powerful and ancient magic. Tom Riddle also stumbles upon this secret. Instead of fighting over it, they decide to explore it together. During this process, they rely on each other's skills and knowledge. This shared adventure builds a deep bond between them, and they start to see each other in a new light, far from their initial impressions.
Nagini's human form could potentially disrupt Tom Riddle's plans. Since she has human emotions in this form, she might not be as blindly obedient as she is in her snake form. For instance, she could show mercy when Riddle wants her to attack someone, which would be a hindrance to his dark plans.
The self - insert could change Tom Riddle's fate by showing him true friendship. In the original story, Tom Riddle was a lonely boy who turned to dark magic. If the self - insert befriends him and is always there for him, it might make him less likely to seek power through dark means.