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.
Maybe Harry Potter decides to sue the Ministry because they have been withholding important information about his family or his true destiny. It could also be that the Ministry has been unjustly persecuting him or his friends, and he decides to take legal action within the wizarding world's framework.
Well, perhaps Harry discovers some dark secrets within the Ministry that are so evil he decides to take it down. Maybe they're involved in some sort of illegal dark magic experiments or corrupt deals with dark wizards.
A possible plot could be that Susan Bones gets a job at the Ministry right after graduating from Hogwarts. She notices some strange activities going on that seem to be related to the return of dark magic. She then reaches out to Harry Potter for help as she believes he has the experience to deal with such things. Together, they start an investigation within the Ministry to uncover the truth.
Hermione Granger would surely be a key character. She is Harry's best friend and is known for her intelligence. She would use her knowledge of magic and laws to try and stop the execution. Ron Weasley would also be important. He would be by Hermione's side, providing his loyalty and bravery. Neville Longbottom could also play a significant role. He has grown into a strong wizard and might lead the resistance within Hogwarts against the Ministry's decision.
Maybe Harry Potter sues the Ministry for false accusations or for not taking proper actions against dark forces. It could also be about some new laws the Ministry made that directly harm Harry or his friends.
Well, perhaps Harry has finally had enough of the Ministry's corruption and inefficiency. So he decides to take it down using his powerful magic skills. He might start by exposing all the dark secrets hidden within the Ministry walls, which could lead to chaos and the downfall of those in power.
Another aspect could be the emergence of new magical laws or lack thereof. Without the Ministry to enforce regulations, magic could be used more freely, but also more dangerously. Some wizards might start experimenting with dark magic without fear of punishment, while others would strive to create a new, more just system of governance from the ground up.
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.
One possible plot could be that Harry discovers some deep - seated corruption within the Ministry. He starts by gathering evidence secretly. Then, he uses his skills and the help of his friends to expose the wrongdoings in a very public way, perhaps through a magically - enhanced news broadcast that reaches every wizarding household, causing great embarrassment to the Ministry officials involved.
If Harry takes over the Ministry in the fanfiction, he could use his experience to better protect the wizarding world. He has faced Voldemort, so he knows the importance of unity. He would probably encourage more cooperation between different wizarding communities. He could also use his popularity to inspire young wizards and witches to be more involved in making the wizarding world a better place, like starting volunteer programs within the Ministry.