The plot could be developed by showing Harry's initial doubts and struggles. Maybe he's offered power and knowledge by the dark side that he can't resist at first. For example, being promised the ability to bring back his dead parents. Then, as he gets deeper into the dark side, he starts to realize the true cost of his actions.
One interesting 'Harry Sold to the Dark Side' fanfiction could be one where Harry is tricked into joining the dark side. Maybe Voldemort manipulates his sense of loneliness after the death of Sirius. Another could involve a magical artifact that compels Harry to side with the dark forces against his will. And there might be a fanfic where the wizarding world turns against Harry, pushing him towards the dark side out of desperation.
If the dark side saves Harry in fanfiction, it could open up a whole new world of story possibilities. Maybe it would involve Harry having to confront his preconceived notions about good and evil and find a way to balance the powers within him.
In some fanfiction, the dark side might help Harry by giving him unique powers. For example, dark magic could offer him abilities that are not available in regular magic, which he can then use to fight against stronger enemies.
One great fanfiction that explores the dark side in the Harry Potter universe is 'The Darkening of Hogwarts'. It delves into what would happen if dark magic seeped deeper into the school. The characters are faced with moral dilemmas and the story shows how the allure of the dark side can be both tempting and terrifying.
Dumbledore could be seen as the main antagonist from Harry's new perspective on the dark side. Dumbledore represents all that is good in the wizarding world, and if Harry has turned to the dark, Dumbledore would be the one trying to stop him, to bring him back to the light. So in this context, Dumbledore becomes the opposition that Harry has to face.
The dark side can offer Harry a different perspective on magic. In fanfiction, this could mean that he starts to see the limitations of traditional 'good' magic and finds new ways to combine or manipulate magic by incorporating elements from the dark side. This can make his magical abilities more versatile and powerful.
Yes, there are likely some out there. Fanfiction often explores unique and unexpected relationships. Some writers might be intrigued by the idea of Harry being Snape's son and delving into the 'dark side' aspects could involve exploring Snape's more complex and perhaps morally ambiguous nature, as well as how that would impact Harry's character and his journey in a different way than in the original story.
Well, perhaps Harry gets tired of being constantly in danger and feeling unappreciated in the wizarding world. He might be lured by the Dark Side with promises of power and safety. Voldemort could offer him a place by his side, showing him a different view of magic that seems more appealing in a warped way.
Well, it could be that the dark side has certain powers or artifacts that end up being the key to saving Harry in fanfiction. Maybe a dark wizard has a magical object that, when used in the right way, can reverse a curse on Harry or help him defeat Voldemort. The dark side's resources, which are often feared and shunned in the normal Harry Potter lore, can be turned into something positive for Harry's salvation in fan - made stories.