Who might be the key characters in a 'Harry Potter executed by ministry' fanfiction other than Harry Potter?

Hermione could be a key character. She is always by Harry's side, and her intelligence and knowledge of the wizarding laws would be invaluable in the lawsuit. She might be the one doing all the research and preparing the legal arguments for Harry.

The Order of the Phoenix members might also back Harry. They've fought against the dark forces before and if they see that the Ministry has become a threat, they'd side with Harry. Dumbledore's old allies in the Order would believe in Harry's judgment and join him in his mission to destroy the corrupt Ministry.

His friends from Hogwarts like Hermione and Ron would most likely support him. They have always been by his side through thick and thin in the original story, so in the fanfiction, they would continue to support Harry in his fight against the Ministry.

Harry Potter himself would likely be a central figure. He has a history of fighting against dark forces and would probably step up to try and maintain order. Hermione would also be important as she is intelligent and could come up with plans to deal with the situation. Ron, with his loyalty and courage, would be by their side.

In this fanfiction, it could be that a new law is passed in the wizarding world. The law states that anyone with the ability to defeat a dark lord must be executed to prevent them from becoming a dictator in the future. Harry, being the only one known to have defeated Voldemort, is targeted by the Ministry. He has to rely on his old Hogwarts allies and some unexpected new friends within the Ministry to fight this unjust law and save his own life.

Neville could play a role too. He has a deep connection to the magical creatures, and he might be sympathetic to Harry's idea of hatching the basilisk. He could offer some advice on how to handle the hatchling based on his own experiences with plants and other less - dangerous magical beings. Also, he could be the one to stand up for Harry when others start to question his motives.

Ron might also be there. He could be the one who offers Harry a place to stay at his own home if Harry is having trouble finding a place. Or, if they've had an argument, Ron could be the reason Harry is moving out in the first place.

He might meet Hermione. Since Hermione is always interested in academic things like Owls, she could be there to help Harry or just be involved in some research related to it.

The Weasley family, especially Arthur Weasley, could be involved. Arthur, being an employee at the Ministry, might know some inside information about Fudge. He could assist Harry either directly or by providing some useful connections within the Ministry to get Fudge fired.

Dumbledore, even if not in person, could have left behind some clues or resources that help Harry. Also, the Order of the Phoenix members who are still around and believe in Harry's cause. They have their own skills and connections that could prove useful. For example, Moody could teach Harry some advanced defensive magic techniques to use against the Ministry's security measures.