Well, in this fanfic, Umbridge might adopt Harry to use him as a pawn in her political games within the wizarding world. She could parade him around as a sign of her 'benevolence' while secretly trying to suppress any signs of rebellion in him. Harry, on the other hand, would be constantly looking for ways to escape her clutches and get back to his real friends and the fight against Voldemort.
One possibility is that Umbridge, despite her cruel nature, sees some potential in Harry for her own gain. Maybe she tries to mold him into a perfect little wizard according to her strict and often wrong ideas. She could isolate Harry from his friends and force him to follow her rules blindly, which would create a lot of internal conflict for Harry as he tries to resist her brainwashing while living under her roof.
In a 'Harry Potter adopted by Umbridge' fanfic, it could start with some sort of legal loophole or magical obligation that forces Harry into Umbridge's care. Umbridge would likely impose her extreme views on discipline and blood purity on Harry. She might even try to rewrite his history of fighting against Voldemort to make it seem like she was the one guiding him all along. Harry would have to struggle not only with her daily abuse of power but also with the false image she tries to create of him in the wizarding community.
One possible plot could be that Marge, despite her initial rough exterior, discovers a soft spot for Harry. She might start to teach him some of her own values, which could be a mix of traditional and rather strict ones. Harry would have to adjust to living in a new environment with Marge's dogs and her no - nonsense attitude.
It could be that the wolves are actually magical wolves with special powers. They sense Harry's unique magic and choose to protect him from the threats he faces in the wizarding world. Harry, while being adopted by them, might discover new forms of magic that are related to nature and the wild, which are different from what he learns at Hogwarts.
In a 'Harry Potter adopted by Newt' fanfic, perhaps Newt gets a mysterious message about a powerful but troubled young wizard. When he finds Harry, he realizes that the boy has a connection to the magical creatures world that he doesn't yet understand. Newt takes Harry under his wing. Harry gets to live in Newt's home, which is filled with all sorts of amazing and dangerous creatures. He learns about their habitats, behaviors, and how to communicate with some of them. This knowledge and his bond with Newt could change the way he approaches challenges at Hogwarts and in the wizarding world as a whole.
It could be that the fanfiction used Harry's likeness without permission in a way that was harmful to his image. Maybe it had Harry involved in illegal or immoral activities that he would never do in the original series, so he decides to take legal action against the author of the fanfic.
Harry's character would face a huge transformation. He'd be constantly on edge, having to deal with Umbridge's strict rules and her mean - spirited nature. This would make him more empathetic towards those who are oppressed. He'd also become more resourceful, finding ways to communicate with his old friends and allies despite Umbridge's attempts to isolate him. His experience with Umbridge would be a crucible that forges him into an even more resilient and determined hero, ready to take on not only Voldemort but also the corrupt elements within the wizarding establishment.
In this fanfic, the plot could center around Harry's identity crisis. He's adopted by wolves, so he has this wild, untamed side, but he also has his wizarding roots. He might struggle to fit in when he finally enters the wizarding world. The wolves could have taught him a different moral code, and he has to reconcile that with the rules and values of Hogwarts. This internal conflict could drive the story forward, with him making new friends who either accept or reject his wolf - like qualities.
The plot could involve Rebbekah protecting Harry from the threats in the wizarding world. Since she has her own set of powers and a rather fierce nature, she'd be a great guardian. Harry, on the other hand, might struggle with adapting to her family's way of life. There could be conflicts within the Meakelson family about Harry's presence too. Some might see him as an outsider, while others might see potential in him, which would create a lot of interesting drama and storylines.
Perhaps he's adopted by a family of house - elves. They teach him their unique brand of magic that is more about domestic and hidden spells. Harry would then have a different perspective on the wizarding world, seeing it from the eyes of those who serve. He could also use this knowledge to help other house - elves gain more rights later on.
The plot might start with Harry being in a vulnerable situation and the Cullens taking him in. They'd have to figure out how to raise a wizard in their vampire household. Harry could start to show his magical abilities which might be both a wonder and a bit of a problem for the Cullens. He could also make new friends in the vampire community, and together they could face some common enemies.
Well, it could be that Harry gets tired of Umbridge's tyrannical rule at Hogwarts. He might start by secretly organizing the students to resist her unfair rules. Maybe he uses his status as the Boy Who Lived to inspire others. For example, he could encourage students to defy her ban on certain magical activities. Then, he might start a campaign of small acts of rebellion, like writing anonymous letters about the truth of what's happening in the school.