In some versions of this type of fanfiction, there could be a time - travel element. Harry travels back in time and ends up getting involved with a younger Voldemort. He sees potential in Voldemort that he believes can be redirected for good, but instead, he gets drawn into Voldemort's dark plans. As a result, he begins to work with Voldemort against the very people he once called friends and allies.
Perhaps Harry joins Voldemort because he believes he can change him from the inside. In this fanfiction, Draco could be the one who initially tries to stop Harry but then realizes that Harry's plan might actually work. They then form an unlikely alliance to bring down Voldemort's more evil plans while Harry is still pretending to be on Voldemort's side.
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.
Yes, it is considered controversial. Harry Potter is traditionally seen as the hero who opposes Voldemort, the ultimate villain. The idea of him joining Voldemort goes against the core values of the original story. Fans of the original series often have strong emotional attachments to the characters as they are in the books, and this concept can be seen as a perversion of those characters.
In such fanfiction, a common plotline is that Harry's decision to join Voldemort creates a power shift. He might use his status as the 'Boy Who Lived' to undermine Dumbledore's reputation further. Since many in the wizarding world had put their faith in Harry, his joining Voldemort could lead to widespread panic and confusion. Harry could also start to recruit other disillusioned wizards to Voldemort's cause, using his own charm and the false narrative that Voldemort is actually a liberator of the wizarding world from the old, restrictive ways.
One possible plotline could be Harry being held captive by Voldemort in a way that's like a pet. Voldemort might use Harry to show his power over the Boy Who Lived. Another could be that Harry has some sort of magic that makes Voldemort keep him as a pet instead of killing him immediately.
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.
In this fan fiction, the plot could involve Harry's abuse leading him to question his previous beliefs. Voldemort, being a powerful figure, might take advantage of Harry's vulnerability. The 'romance' could be a complex web of power dynamics and emotional manipulation. For example, Voldemort might use his charm and knowledge to draw Harry closer, and Harry, in his state of confusion and hurt from the abuse, might be swayed into believing that there is something more to their relationship than just power - seeking.
One possible plotline could be that Harry Potter somehow finds himself in Gotham City and crosses paths with Bruce Wayne. They could initially be at odds due to their different methods of dealing with problems, but then gradually come to understand and respect each other, leading to a deeper relationship.
Perhaps Harry is held captive in a hidden location by Voldemort. While being tortured, he has visions of his past and the sacrifices his parents made. This gives him the strength to resist Voldemort's attempts to break his will. His friends then embark on a dangerous quest to find him based on these visions Harry manages to send out magically.
Maybe Harry joins Voldemort because he discovers some dark secrets about the so - called good side in the wizarding world. He might think that Voldemort's way of ruling could bring a new order that is more just in his eyes. However, he soon realizes that Voldemort's true nature is far more cruel than he expected, leading to a conflict within himself.