In some fanfictions, Harry discovers a long - forgotten magic charm that has the power to make a person's worst nightmares come true. He uses it on Umbridge, and she is so terrified by the nightmares that she runs away from Hogwarts. The charm could be something that is based on the person's deep - seated fears, and for Umbridge, it might be related to losing her power and being publicly shamed.
Snape could face some backlash from the Ministry. If they find out that he was involved in getting rid of Umbridge, they might try to find ways to punish him or at least keep a closer eye on him. However, his skills at subterfuge would likely help him avoid any serious consequences.
In some versions, Snape uses his knowledge of the Dark Arts and Hogwarts' secrets. He might set up a situation where Umbridge is lured into a restricted area of the castle and gets into trouble with some magical creature or ancient magic, causing her to be removed from her position.
In some fanfictions, Harry might use his powerful magic skills, like advanced spells he's learned secretly, to outwit Umbridge. For example, he could create a series of complex illusions that confuse her and lead her to leave Hogwarts on her own.
Hermione is a must. Her intelligence and extensive knowledge of magic and Hogwarts rules would be invaluable. Ron would be involved too. He's Harry's close friend and has a bit of a mischievous streak himself. Fred and George Weasley are very likely to be part of it. They are known for their love of pranks and their dislike of authority figures like Umbridge. Luna Lovegood could also be included. She has a unique perspective and might come up with some really out - of - the - box ideas for Harry's revenge on Umbridge. Plus, her presence would add an interesting and somewhat dreamy element to the whole revenge plot.
In some fanfictions, Harry might use his magic skills in a creative way to embarrass Umbridge. For example, he could make her signature pink outfits turn into ridiculous colors every time she tries to be authoritative. Another scenario could be that Harry reveals some of Umbridge's darkest secrets in front of the whole school, which would surely be a form of revenge as she values her reputation so much.
Fred and George Weasley are also favorites. Their mischievous nature can be amplified in fanfictions. They could create new and even more spectacular magical pranks specifically aimed at Umbridge, like turning her office into a never - ending maze of trick stairs and hidden rooms filled with various magical creatures that drive her crazy.
Another idea is a time - travel fanfiction. Harry goes back in time and has to deal with Umbridge when she was a student. He tries to change her path so that she doesn't become the horrible person she is in his time. This could involve him befriending her and showing her the value of kindness and freedom.
Well, he could use the power of friendship. Maybe with the help of his friends like Hermione and Ron, they come up with a plan. They might find evidence that Snape has been involved in some really bad things that go against the wizarding laws. Once they present this evidence to the proper authorities, like Dumbledore or the Ministry of Magic, Snape could be gotten rid of. Also, Harry might have some sort of prophetic dream that gives him the key to getting rid of Snape, just like he had dreams about Voldemort in the original series.
There's also a fanfic called 'Umbridge Unmasked'. This one shows a different side of Umbridge. Instead of just being a one - dimensional villain, it explores her insecurities and how they drive her actions. It's an interesting take on her character that makes you think more about her role in the wizarding world.