Ron Weasley would be another key character. His hot - headedness might initially cause problems when Draco tries to join the good side. But as the story progresses, Ron could come to see Draco's value. Additionally, Dumbledore (even if only in spirit or through memories) could be important. His wisdom and understanding could guide Draco on his new journey, and Draco might look to Dumbledore's ideals as he tries to make amends for his past actions.
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.
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.
Hermione could be a main character. Given her strong stance on equality, she might initially be suspicious of Draco but later come to understand his internal struggle as a half - blood. Their interactions could be filled with tension and, eventually, mutual understanding.
Another possible main character could be Snape. Given Snape's complex relationship with Draco in the original series, in this fanfiction, he could be either a mentor to Draco in his prodigious journey or have a more conflicted role as he tries to balance Draco's new status with the existing power structures in Hogwarts.
Harry Potter could be one of the main characters. Since he has a complex relationship with Draco, he might be intrigued by Draco's sleep - talking and try to use it to gain some understanding of Draco or even to tease him.
His father, Lucius Malfoy, might also be a main character. Lucius, who is always so concerned about appearances and family reputation, would be horrified by Draco's slobbishness. There could be a lot of conflict between them as Lucius tries to force Draco to be presentable again. And then there's Hermione Granger. Since she's always so neat and organized, she might be appalled by Draco's slobbish ways and get involved in some sort of rivalry or strange friendship with him because of it.
Hermione could be a main character. She might be the one who first suspects Draco's new role as the chosen one. Hermione's intelligence and inquisitive nature would lead her to notice the strange things happening around Draco. She could either be an ally or a skeptic, depending on how the story unfolds.
The family house - elf could be an important character. It could be the one who takes care of the family home and the kids when Harry and Draco are away on magical business. It could also be a confidant for the children, listening to their problems. And Dumbledore's ghost could make an appearance. He could offer some cryptic advice to Harry and Draco about raising their family in the wizarding world, guiding them to make the right decisions for their family's future.
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.
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.
There could be some original Muggle characters created just for the fanfiction. Maybe a friendly Muggle neighbor who is always curious about Draco's strange ways and in turn, makes Draco curious about the Muggle world. This neighbor could introduce Draco to things like Muggle sports, like football, which Draco would find both strange and exciting.