Perhaps Harry has been abused by a group of rogue wizards who are after his fame. Voldemort, seeing an opportunity to gain some sort of advantage, saves Harry. This starts a journey where Harry and Voldemort form an uneasy alliance. Voldemort may try to manipulate Harry's trust, while Harry tries to figure out Voldemort's true motives and also how to use this situation to make the wizarding world a better place.
One plot idea could be that Voldemort saves Harry from his abusers in the Dursley household because he realizes Harry's potential is being squandered there. He then takes Harry under his wing, not to turn him evil, but to train him in magic in a very different way than Hogwarts. Maybe he wants to use Harry as a tool against the Ministry, which he believes is corrupt.
Another possibility is that Harry is being physically and emotionally abused at Hogwarts by some dark forces that have infiltrated the school. Voldemort, for his own mysterious reasons, decides to rescue Harry. This could lead to a complex relationship where Harry is both grateful and conflicted, and Voldemort has to deal with his own Death Eaters who don't understand his new 'ally'.
Harry's character would likely become more complex. Initially, he might be distrustful of Voldemort's motives but also feel a sense of obligation for being saved. This could lead to him being more cautious and calculating in his actions, as he has to navigate the dangerous waters of being associated with the Dark Lord.
One possibility could be that Voldemort has a sudden change of heart. Maybe he realizes that Harry is the only one who can truly understand his loneliness and power. So instead of killing Harry, he decides to save him from a dangerous situation, like a powerful dark magic that even Voldemort fears could destroy the wizarding world if not controlled, and in the process, they form an unlikely alliance.
One possible plot point could be Voldemort's change of heart. Maybe seeing Harry being abused makes him question his long - held enmity towards Harry. He might start to see Harry as more of a victim than an enemy, which could lead to some really strange alliances or at least a change in his approach towards Harry.
One idea could be that Harry starts having strange dreams where he sees through Voldemort's eyes. This could lead to him unknowingly helping Voldemort in some small ways at first, like revealing the location of some minor Order of the Phoenix safe houses. Another plot could involve the other characters slowly realizing something is wrong with Harry. For example, Hermione might notice that Harry is using some Dark Magic spells without hesitation, which is completely out of character for him.
A plot could involve a magical creature that bonds Harry and Voldemort in an unexpected way. For example, a rare faerie that makes them see each other's memories. Through this, Harry discovers some long - hidden secrets about Voldemort's past that could potentially change the course of their enmity. They then have to decide what to do with this new - found knowledge.
Yes, there are some fanfictions with this concept. It's an interesting take on the Harry Potter universe as it flips the typical relationship between Harry and Voldemort. In these fanfictions, the story often explores how Voldemort's actions change when he takes on the role of an adoptive figure to Harry, who has been abused. It can lead to some really unique character developments and plot twists.
One possible interesting plot point could be Harry's internal struggle. On one hand, he has been raised in an abusive situation, and on the other, he discovers this shocking relation to Voldemort. He might struggle with his own identity and whether he has the potential for evil within him like his supposed father.
One popular one might be 'Voldemort's New Heir' where Voldemort discovers Harry's abused situation and decides to take him in for his own purposes. He starts to train Harry in dark magic, but an unexpected bond forms between them.
One possible plotline could be that Harry, after being abused, feels a sense of desperation and a lack of support from the good side. He might be lured by Voldemort's power and the false promises of a new order where he won't be abused. Voldemort could manipulate Harry by showing him a different way of life, perhaps one where he has more control and respect.
Perhaps in the fanfiction, Voldemort's reincarnation is born into a more humble family and through his new life experiences, he starts to question his past actions. Harry, on the other hand, is intrigued by this new Voldemort and they embark on a journey of self - discovery together, exploring the gray areas between good and evil.