Hermione would probably be devastated. She was Harry's closest friend and ally. She might be filled with rage towards Vernon and vow to seek justice. Ron would also be heartbroken and might want to take matters into his own hands against Vernon.
In this fanfiction scenario, it could be that the writer decided to change the power dynamics completely. Vernon, who is usually just a Muggle bully in the original, might be given some unexpected power or weapon in the fanfic. And Harry, perhaps caught off - guard or having lost his magic temporarily, could be killed by Vernon. It shows how fanfiction can turn the whole story upside down.
Harry Potter might be a bit surprised. He'd probably think it's strange that people are writing about his friends' and his own relationships in such a different way. Hermione would likely be very interested in the writing style and how the authors are creating these new relationships. She might even take notes to improve her own writing. Ron would just laugh it off most of the time. He'd find it a bit odd but also funny.
Hermione would probably be shocked and confused. She would try to find a logical explanation through research. Ron might be disgusted at first, as he has a traditional view of relationships. Dumbledore, being the wise and understanding figure, would likely try to see the bigger picture and find a way to protect Harry from the potential fallout. The Malfoy family would be in a state of chaos, with Narcissa having mixed feelings about the situation.
Hinata would be heartbroken. She loves Naruto deeply. Her world would shatter. She might try to find out the truth behind his death, not believing that his friends could do such a thing without a good reason. And she would probably hold a grudge against those involved.
Luna would be very open - minded. She might see the fanfiction as just another form of magical thinking. She could find the wild and imaginative ideas in the fanfictions quite endearing and might even start to incorporate some of the concepts into her own unique view of the wizarding world.
Hermione would probably be shocked at first. But then she would try to find a way to help Harry through it, using her vast knowledge of magic to figure out what's going on.
Sasuke would likely be enraged. He and Naruto had a complex relationship, and Naruto was like a brother to him. He would probably seek revenge on Sakura immediately. Kakashi, as their teacher, would be deeply shocked and disappointed. He might struggle to understand how Sakura could do such a thing. The villagers would also be in turmoil. Naruto was their hero, and his death at Sakura's hands would cause a great deal of confusion and anger among them.
In this kind of fanfiction, perhaps Harry, out of fear or some form of coercion, starts to obey Uncle Vernon's every order. Maybe Vernon uses threats about expelling Harry from the house or withholding food to make him submit. This could lead to a very different dynamic in the Dursley household, with Harry being more submissive and not showing his usual defiance.
Well, he might be really confused at first. Supernatural has all these different monsters and a very different magic system compared to his world. He'd probably be intrigued by the way the Winchester brothers deal with things though.
One possible plotline could be that Harry uses his magic in self - defense and this leads to a whole new set of challenges as he tries to hide it from the wizarding world while dealing with Vernon's continued abuse. Another could be that the Dursleys finally get caught by the wizarding authorities for their mistreatment of Harry, especially Vernon's torture.