They might be really surprised. The Avengers are used to their own set of adventures, and this fanfiction about 'The Impossible' would show them in a whole new scenario that they may not have expected. It could be both exciting and a bit strange for them to see this new take on their characters.
The Avengers would likely have a range of reactions. Captain America, being the more traditional one, might be a bit taken aback by any radical changes to their storylines in the fanfiction. But Hulk, in his own simple way, could either be indifferent or just get excited by all the action. And Black Widow might see it as an interesting study of how the public perceives them through this fan - created story.
Some relationships might be tested. If the fanfiction portrays one Avenger in a bad light or has a conflict between two of them that's different from what they know, there could be some tension. But they'd also realize it's just a fan's interpretation. Hawkeye might be a bit miffed if the fanfiction makes him seem less important, for instance.
They might be surprised at how their actions are reimagined. For example, Iron Man could be astounded to see a version of himself in a situation he never thought of in the official storylines.
The Avengers might also be a bit critical. Hawkeye might notice inaccuracies in the way his skills are described in some fanfictions. He could be thinking, 'I don't use my arrows like that!' And Captain America might be disappointed if a fanfiction goes against the core values he represents in the movies. He would probably prefer stories that uphold the idea of justice and loyalty as he does, rather than those that distort it for the sake of a wild plot.
They might be quite intrigued. Some Avengers could be impressed by the creative interpretations of Wonder Woman's character in the fanfiction. For example, Thor might find the new and unique storylines exciting, as he is used to grand adventures in his own world.
In fanfiction, the Avengers could have a range of reactions. Hulk might not care much about the drama but be more interested in the destruction. Black Widow would probably be analyzing every move, looking for any weaknesses in the villains' plans. Captain America could be feeling a bit out of place with all the modern technology. And Iron Man himself? The others might be in awe of his ability to keep going despite all the odds against him in the movie.
Well, the Avengers could have a whole range of reactions. For instance, Tony Stark might be analyzing the science behind the events in 'No Way Home' and thinking of ways to use or improve it. Captain America could be more focused on the moral implications of bringing back the villains and how they are being dealt with. Thor might just be enjoying the chaos and action, seeing it as a great spectacle.
Well, they might be impressed by John Wick's badassery in the fanfiction. Tony Stark would probably make some sarcastic comments about the action scenes. Thor might compare John Wick's combat skills to his own. And Natasha would be analyzing the stealth and strategy elements.
Well, Tony Stark might be making sarcastic comments throughout. He'd probably point out any scientific inaccuracies in the fanfiction compared to the real Hulk. Like, 'Oh, come on, that's not how the Hulk's gamma radiation works at all!'
They might be amused. The Avengers know Tony Stark well, and seeing different interpretations of his character in the Iron Man 2 fanfic could bring out some laughter. They may also be critical in a friendly way, like pointing out things that are not in line with what they know about Stark or the events in Iron Man 2.
The Avengers could be intrigued. They might see some similarities between Moon Knight's fight against evil in the fanfic and their own battles. Captain America, for example, would probably admire Moon Knight's determination in the face of danger, even if he doesn't fully understand all the Egyptian mythology stuff that's often part of Moon Knight's story. Thor might be interested in any connections to the otherworldly elements in the fanfic, comparing them to his Asgardian knowledge.