She's often portrayed as extremely cruel. She uses her position of power at Hogwarts to make Harry's life miserable. For example, she might give him excessive detentions with the blood - quill, just like in the original books. And she'll try to isolate him from his friends and undermine his credibility among the students and teachers.
In these fanfictions, Umbridge is typically depicted as a tyrant. She has no qualms about using her authority to target Harry specifically. She'll spread false rumors about him, manipulate the school rules to her advantage, and be very strict and unforgiving in her punishments towards him. She might also be shown as having a sadistic streak when it comes to dealing with Harry, enjoying seeing him suffer.
In some fanfictions, Harry might get Umbridge arrested by exposing her illegal and cruel actions towards students. For example, he could gather evidence of her misuse of power in punishing students with the blood - quill and present it to the proper authorities in the wizarding world.
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.
Perhaps in the fanfic, Harry teams up with the other students to stage a large - scale protest against Umbridge. Their united front and the chaos it causes might lead to the school board or the Ministry of Magic realizing that she is not fit to be in charge at Hogwarts. Or Harry could use his connections, like his friendship with Sirius or the Order of the Phoenix members. They could dig up some dirt on Umbridge from her past that makes it impossible for her to continue teaching at Hogwarts.
The development of their relationship in Harry and Umbridge lemon fanfiction can be quite diverse. It could be that Umbridge, in an attempt to control Harry more closely, gets drawn into his world in a way she didn't expect. Harry, on the other hand, might start to see through her tough exterior and find some vulnerability in her. This discovery could lead to a series of exchanges between them, some filled with tension, some with a strange sort of understanding, and over time, this shapes their relationship in the fanfiction.
Another way Harry could respond is with a sense of shock and disbelief at first. Given that Umbridge is supposed to be in a position of authority, Harry might be momentarily stunned that she would go to such lengths. However, his Gryffindor courage would soon kick in, and he would likely start to resist, perhaps by using his magic in creative ways to protect himself or to disarm Umbridge, all while trying to uphold the values of the wizarding world that oppose such cruel and unjust treatment.
Hermione might also try to turn the situation around to expose Umbridge's tyranny. She could gather evidence of Umbridge's improper behavior during the punishment process and then use it to convince the other teachers or even the headmaster that Umbridge is a bad influence in the school. This would be in line with her intelligent and problem - solving nature.
In some fanfictions, Harry might outsmart Umbridge by using his knowledge of magic in unexpected ways. For example, he could use spells that are not commonly known to get around her rules. Maybe he uses a charm to make her quill write false reports, thus confusing her when she tries to use those reports against him.
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 certain fanfictions, Harry could get out of trouble with Umbridge through the power of truth - telling spells. He might be able to prove his innocence by using a spell that forces the truth to be revealed. Also, there could be instances where magical creatures come to his aid. For example, if he has befriended some of the magical creatures on the grounds, they could cause a commotion that diverts Umbridge's attention long enough for Harry to get away. Maybe a group of pixies start causing chaos in her office, and while she's trying to deal with them, Harry slips away unnoticed.
Umbridge's Luddite nature could be shown through her strict opposition to any new or non - traditional magic at Hogwarts. For example, if a student were to introduce a new spell that made studying easier, she would immediately ban it, citing it as against the 'old ways' of magic.