In a 'Draco switches sides' fanfiction, it might start with Draco being disillusioned with his family's long - standing loyalty to Voldemort. His experiences at Hogwarts, especially his interactions with some of the more morally upright students like Hermione or Harry, could gradually nudge him towards the other side. He might first resist the idea but then, after a major event, such as seeing an innocent person being brutally attacked by Death Eaters, he decides to switch sides and use his position within the Death Eaters to undermine them from within.
Perhaps Draco begins to question his allegiance when he is given tasks by Voldemort that are too heinous for him to carry out. For example, he is ordered to kill a fellow student or a teacher. His conscience gets the better of him. He starts to make connections with the good side, initially in a very cautious way. He might leave small hints or clues for the good guys to find, which eventually leads to him fully switching sides and actively fighting against Voldemort and his followers.
Harry Potter would surely be one of the key characters. His relationship with Draco, which has always been a mix of rivalry and grudging respect, could play a huge role. As Draco switches sides, Harry would be initially suspicious but then come to accept and work with him. Hermione Granger is also likely to be important. Her intelligence and strong moral compass could influence Draco further and she could be the one to first recognize his change of heart.
One way Hermione could switch sides in fanfiction is through a major misunderstanding. For example, if the wizarding world turned against her for some false accusation, she might feel betrayed and be pushed towards the 'dark side'. Maybe she discovers that the so - called 'good guys' have been hiding some dark secrets that go against her moral code.
Another plotline could involve Harry being betrayed by the Order of the Phoenix. Feeling hurt and lost, he decides to side with Voldemort out of revenge. However, as he gets closer to the dark side, he realizes that Voldemort's true nature is far more evil than he thought and has a change of heart.
One interesting scenario could be Harry realizing that the so - called 'dark side' has been misrepresented. Maybe he discovers that the Death Eaters have some valid grievances against the Ministry's corruption, which makes him question his allegiance. Another could be that he's influenced by a powerful dark magic artifact that makes him see things from Voldemort's perspective, at least temporarily.
Obviously, Harry Potter himself is the central character as the title implies. Voldemort is also often involved as the main figure on the 'dark side' that Harry might switch to or interact with differently. Then there's Snape. His complex relationship with Harry could be a key factor in the story. In some fanfictions, he might be the one who either tempts Harry to switch sides or tries to prevent it depending on his own motives.
Obviously, Harry Potter himself is the central character as the story revolves around his switching sides. Hermione and Ron also play significant roles. When Harry starts to show signs of siding with the dark side, Hermione might try to use her intelligence to figure out what's wrong and bring him back. Ron, on the other hand, could be more impulsive in his reactions, either trying to fight Harry if he becomes a threat or trying to persuade him to return to the good side.
Another possibility is that Draco falls in love with a character from the opposing side. His love could be so strong that it overrides his loyalty to his original side, leading him to change. For example, if he falls for a Gryffindor, he might start to see things from their perspective and gradually shift his allegiance.
His relationship with his family would be severely strained. His parents, who were loyal to the Dark side, would be shocked and disappointed. They might even try to persuade him to come back, which could lead to a lot of family drama.
One interesting plot development could be the characters' initial confusion and hilarity. Naruto, suddenly in Moka's body, might struggle with her more feminine mannerisms and powers. For example, if Moka has vampire abilities, Naruto would have to quickly learn to control them. Meanwhile, Moka in Naruto's body would have to deal with his ninja skills and the expectations of his friends. They could also learn valuable lessons about each other's lives, like Naruto understanding the difficulties Moka faces as a half - vampire, and Moka realizing the pressure on Naruto to protect his village.
In some of these fanfictions, a great plot twist is when Hermione's switch to Slytherin causes a rift among her old Gryffindor friends. However, this rift actually leads to a deeper understanding between the houses in the long run. She might also start to question the values she was taught in Gryffindor and find that Slytherin has some values, like ambition in a positive sense, that she can really embrace. And there could be a plot where she has to use her new - found Slytherin knowledge to save Hogwarts from a threat that Gryffindor - centered magic couldn't handle.