He could be intrigued. Fanfiction often has creative twists. He may find new perspectives on his relationships with his friends and family in the epilogue fanfiction. For example, if it delved deeper into his relationship with Ginny, he might gain a new understanding of their bond. He would also be curious about how the author of the fanfiction envisioned the next generation of wizards.
He might be shocked. The fanfiction could have ideas that are completely contrary to his understanding of the future in the wizarding world.
The marauders' reaction would be quite complex. They might feel a sense of nostalgia as they read about the world they once knew, but through a different lens in the fanfiction. They could also be a bit critical. If the fanfiction didn't seem to respect the essence of the original story, they might be quick to point it out. However, if it was well - written and added new depth to the story, they could end up really enjoying it and even discussing it at length among themselves.
He could be shocked. Maybe there are some fanfictions that take a very dark turn or have unexpected pairings that he never thought of. He'd probably need some time to process such strange ideas. And he might also be curious to see how far the creativity of the fans can go. He might even get some new ideas about his own life from reading some of the more imaginative fanfictions.
Tony would likely laugh at some of the more out - there plot ideas. He'd probably think he could come up with better technology than what's in the fanfic. Steve would be more open - minded and might enjoy the creativity. Thor would be like 'This is not like any Midgardian story I've heard!'.
Some Avengers might be amused. For instance, Tony Stark would likely find it a fun distraction from his usual high - tech world and might even make sarcastic comments about the plot or characters. He could say something like 'These wizards should really upgrade their transportation - brooms? Seriously?'.
Draco Malfoy would probably be outraged at first if he read fanfiction that showed him in a positive light towards Harry and his friends. He's so used to being on the opposite side, but then he might secretly be a bit flattered by some of the more complex characterizations of him.
Some of them would be entertained. Iron Man might laugh at the strange spells and potions. Hulk might not understand much but could enjoy the action parts if there are any. Thor could be curious about the magic and how it compares to his Asgardian powers.
One benefit is getting more character development. Fanfiction often delves deeper into the characters' post - Hogwarts lives. For example, it might explore how Harry copes with his fame in a more detailed way than the original epilogue. Another advantage is exploring different storylines. Maybe in fanfiction, we can see alternate relationships or adventures that the official epilogue didn't touch on.
The Black family's reaction to reading Harry Potter fanfiction would likely be mixed. There could be those who are immediately drawn in by the unique ideas and character developments that fanfiction often presents. They might be happy to see different takes on the magical world they are part of. On the other hand, there are likely members who hold the original books in high regard and see fanfiction as a distortion of the 'true' story. They may feel that it undermines the integrity of the wizarding world as J.K. Rowling created it. There could also be some in - between, who are initially skeptical but then start to appreciate certain aspects of the fan - created stories.
He'd probably be furious. Voldemort has a huge ego and most fanfiction would likely not portray him in the way he sees himself. He might view it as a form of disrespect to his 'true' nature and power.
She'd be appalled. Umbridge is all about following the rules and maintaining the status quo. Fanfiction doesn't adhere to the official canon she so firmly believes in.