In a more out - of - the - box scenario, Voldemort could rescue Harry Potter due to a prophecy. The prophecy might state that if Harry dies in a certain way, it will bring about the end of the wizarding world, including Voldemort's own existence. So, Voldemort decides to keep Harry alive by rescuing him from a dangerous situation. This would completely change the dynamic between them, and the two might have to work together in some way to avoid the predicted doom.
Perhaps Voldemort rescues Harry Potter as part of a complex mind game. He wants to break Harry's spirit and make him turn to the dark side. By saving Harry's life, he plants the seed of doubt in Harry's mind about the good side. Harry might start to question the motives of Dumbledore and his friends. This could lead to a lot of internal conflict for Harry as he struggles between his loyalty to his old friends and the 'debt' he feels towards Voldemort for saving him.
One possibility could be that Voldemort rescues Harry Potter for some self - serving reason. Maybe he realizes that Harry holds the key to a greater power that he wants to obtain. So, instead of killing Harry, he saves him from another threat, like a powerful dark wizard who is trying to overthrow Voldemort and sees Harry as a useful tool as well. In this fanfiction, Harry would be in a very strange situation, having to trust Voldemort at least temporarily.
The relationship would become extremely complex. Harry would no longer be able to simply see Voldemort as pure evil. He would be in a state of confusion and moral dilemma. Voldemort, on the other hand, might start to view Harry as a more interesting pawn rather than just an enemy to be killed. They could develop a strange sort of respect for each other, at least on a surface level.
One possible plot could be that Harry is wrongly accused of a crime in the wizarding world, perhaps something related to dark magic. The police, who might be a new magical law enforcement unit, rescue him from an angry mob. They then help him clear his name by finding the real culprit, who could be a Death Eater in disguise trying to frame Harry to cause chaos in the post - Voldemort era.
The plot could involve the goblins rescuing Harry when he is being wrongly accused of a crime in the wizarding world. They could believe in his innocence and use their unique skills and knowledge of magic to keep him safe. Maybe they help him prove his innocence later on. They might also have their own motives for helping Harry, like they see him as a key to some sort of change in the relationship between wizards and goblins.
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.
Maybe a plot could involve a powerful spell that binds their fates together and they have to learn to live with each other. Eventually, they might start to understand each other's motives and fall in love.
Perhaps Harry joins Voldemort out of a sense of hopelessness. After seeing so much destruction in the wizarding world, he might think that joining Voldemort is the only way to end the war quickly. However, he soon realizes that Voldemort's methods are too extreme and tries to find a way to turn things around from within the dark side.
In this kind of fanfiction, perhaps Harry is rescued by the Order of the Phoenix earlier than in the original story. They might have realized the Dursleys' mistreatment sooner. Then Harry could start his magical training earlier, away from the hostile environment of the Dursleys' home. He may also form closer bonds with other members of the Order, like Sirius, who could play a more active role in his upbringing.
One possible plotline could be that Voldemort rescues Harry because he sees potential in him to be a powerful ally in his quest for total domination. Harry, being evil, might have already started to dabble in the Dark Arts on his own and Voldemort wants to harness that. Another plotline could be that Voldemort saves Harry from some other threat, like the Ministry of Magic which has turned against Harry for his evil deeds. This could lead to a strange alliance between them as they both have a common enemy in the Ministry.
Perhaps in this fanfiction, Harry discovers some dark secret about the Order of the Phoenix or Dumbledore that makes him lose faith in the side he has always been on. This, combined with Voldemort's manipulation, could lead him to side with the Dark Lord. For example, if he finds out that Dumbledore has been using him all along without his full knowledge, he might be so disillusioned that he turns to Voldemort as an alternative.
In this fanfiction scenario, it could be that Voldemort was misunderstood due to a long - standing feud between two powerful wizarding families. The real motives of Voldemort were to bring equality among all wizards, regardless of their blood status. Harry, who has always fought for justice, sees the potential in this 'good' Voldemort and decides to join him. They then start a journey to change the perception of the wizarding society towards Voldemort and his ideas.