There could also be other Hogwarts students involved. For example, Hermione and Ron might be worried about Harry and try to find out what happened to him. They could even end up interacting with the Malfoys in some way, perhaps initially suspecting the Malfoys' motives but later realizing they are on the same side, at least for the time being. This would add more drama and conflict to the story.
I think Dobby could also be a significant character in this fanfic. Since he has connections to both the Malfoys and Harry. He might be the one who gives the Malfoys the idea to rescue Harry or helps in the rescue in some way. Also, Voldemort or his Death Eaters could be important in the background as the threat that Harry needs to be rescued from. Their presence would constantly loom over the story, making the Malfoys' actions more dangerous and significant.
Obviously, Harry Potter is the central character. Then there are the Malfoys - Lucius, Narcissa, and Draco. Hermione and Ron might also be involved, perhaps as characters who are initially suspicious of Harry's new situation but later come to understand it.
Obviously, Harry Potter is one of the main characters. He is the one who is being helped by the Malfoys. Then there are the Malfoys themselves. Lucius Malfoy, with his knowledge of the dark wizarding world and connections among the Death Eaters, could play a crucial role. Draco Malfoy is also important as his relationship with Harry has always been complex and in this fanfic, it might be a key factor in his family's decision to help Harry.
Obviously, Harry Potter himself is a main character as he is the one being rescued. Then there would be the Delacours, mainly Fleur Delacour. She is a strong and resourceful witch. Her family members, like her sister Gabrielle or her parents, could also be involved in the rescue. They might work together as a family to save Harry.
Well, one possible plot development could be that the Malfoys, in rescuing Harry, have a change of heart towards the whole fight against Voldemort. Maybe they start to see the error of their ways and side with Harry more openly. For example, they could use their influence in the wizarding world to help Harry gather more allies.
The main characters would be Hermione and the Malfoys. Hermione, being the intelligent and strong - willed Gryffindor. Among the Malfoys, Draco would be at the forefront. He has his own insecurities and growth arc that can be intertwined with Hermione's stay. Narcissa could act as a mediator of sorts between Hermione and the more hostile members of the family like Lucius, who might initially see Hermione as a threat to their pure - blood ideals.
Obviously, Harry Potter and Voldemort would be the main characters. Since it's about an 'evil Harry Potter', he would be a central figure with a different personality than the canon Harry. He might be cruel, power - hungry and have a disregard for the rules of the wizarding world. Voldemort, on the other hand, would be the rescuer, perhaps seeing Harry as a tool or a kindred spirit in his evil plans.
Obviously, Harry Potter himself would be a main character. Elrond, who is raising Harry, would also be a central figure. There might also be other elves like Arwen, Elrond's daughter, who could play important roles. Maybe some of Harry's friends from Hogwarts could make appearances in the story, even if it's just in his memories.
Harry Potter himself could be a main character. He has a history of standing up against injustice, so it's likely he'd be involved in a revolt. Hermione would also be a key figure. Her intelligence and knowledge of the wizarding world's laws would be invaluable in planning and leading a revolt. Ron, with his loyalty and courage, would be right there with them.
Harry Potter would probably be one of the main characters. He's the central figure in the original series, so it's likely he'd be involved in this fanfic in some capacity, perhaps as the hitman or someone related to the hitman - style plot.
Harry is the central figure in 'harry turns into a snake fanfic'. In addition to his closest friends, there could be some new characters introduced. For instance, an old wizard who specializes in transfiguration gone wrong. This wizard could be a hermit living on the outskirts of the wizarding world. He might have the key to understanding Harry's transformation and reversing it. And we can't forget the snakes themselves. There could be a particularly intelligent snake that befriends Harry in his new form and helps him in his journey.