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.
If Harry Potter joins the dark side in fanfiction, it would completely颠覆 the original story. His friends would become his enemies, and Hogwarts would be in chaos. The power dynamics in the wizarding world would shift, and Voldemort might see Harry as a valuable ally or a potential threat to his own leadership. It's a very interesting concept to explore in fanfiction.
Well, one possibility could be that Harry, feeling betrayed by the Order of Phoenix or perhaps influenced by some dark magic artifact, starts to question the motives of the good side. He might see how the Dark side offers power and a different kind of 'freedom'. For example, Voldemort could manipulate Harry by showing him how the wizarding world could be united under his rule, eliminating the in - fighting among pure - bloods, half - bloods and Muggle - borns, though of course this would be a false promise.
It could be Dumbledore. In a twisted take on the story, if Harry joins the dark side, Dumbledore would be the one trying to stop him. Dumbledore has always been the guiding force for the good side, and Harry's defection would be a huge blow. Dumbledore would then have to face the difficult decision of either trying to save Harry or stopping him by any means necessary, making him the antagonist from Harry's new 'dark' perspective.
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.
Obviously, Harry Potter himself would be the central character. Then, Voldemort would be a major figure as he is the main representative of the Dark Side. Bellatrix Lestrange could also play an important role as she is one of Voldemort's most loyal followers. She might be the one to initially tempt Harry or guide him into the ways of the Dark Side.
When Harry Potter joins the dark side in fanfiction, the wizarding world undergoes a major transformation. Fear would spread among the good wizards and witches. Dark magic would likely become more prevalent as Harry's influence could encourage others to explore it. The balance between good and evil would be severely disrupted. The families of Harry's friends would be in danger, and there might be a split within the Hogwarts faculty on how to deal with him. Also, the centaurs and other magical beings might get involved, either siding with the dark side because of Harry or trying to stop him to protect their own interests.
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.
The teachers at Hogwarts, like Dumbledore (if he were still alive in the fanfic), would be deeply concerned. Dumbledore always saw great potential in Harry for good. He would probably try to understand what led Harry to this path and would use all his wisdom and magic to try and turn Harry back. The other teachers would also be on high alert, fearing for the safety of the students and the future of the wizarding world.
Perhaps Harry discovers some dark secrets about the wizarding world that make him lose faith in the good side. For example, he might find out that some of the so - called good wizards have been involved in immoral acts. This disillusionment leads him to think that the dark side might be a better option. As he joins them, he starts to abuse his power, using dark magic to get revenge on those who he believes have wronged him.