Tony Stark would probably be really critical at first. He'd be looking for any plot holes or scientific inaccuracies. Thor might be a bit confused at some of the more modern or out - there concepts. Captain America, on the other hand, would be more interested in how the fanfics uphold the values he believes in.
A villain like Shigaraki would likely be interested in the power levels in the MCU fanfiction. He's always looking for ways to increase his own power, and seeing the various powerful artifacts and abilities in the MCU might give him some ideas. He could think about how he could use similar things in his own plans to take over the MHA world.
Loki could also show signs of fear, though he would try to hide it. Inside, he knows the power that Thanos wields. But on the outside, he would maintain a facade of bravado. His reactions would be a mix of his natural cunning and the instinct to survive in a very dangerous situation.
Loki might react with anger. He could seek revenge against Odin, plotting ways to undermine his power or expose his wrongdoings. This reaction is common as it shows Loki's pride and his unwillingness to be a victim.
Loki could be surprisingly empathetic. He would see a bit of himself in Peter, perhaps, as someone who has been misunderstood. So he'd try to befriend Peter and give him advice on how to handle the bullies without using violence, like using his intelligence.
Well, Thor might be a bit shocked at first. He'd probably be amused by some of the wilder interpretations of his brother in the fanfiction. Captain America, on the other hand, would likely be confused by the whole concept as it's so different from the traditional stories he's used to. Iron Man would probably make sarcastic comments about how creative the fans are in coming up with these stories.
They would be confused. The way the MCU has different Earth - based settings compared to the galaxy - spanning settings of Star Wars would throw them off. Han Solo might make jokes about how small - scale some of the MCU battles seem in comparison to the space battles he's used to.
Loki might initially be shocked. He's used to being the one in control and causing chaos, not the one on the receiving end of pain from mortals. He could be filled with rage and vow revenge against Shield, using his wits and remaining magic to plan a counter - attack.
Loki's survival might also lead to a shift in power dynamics. In the Asgardian remnants, he could emerge as a leader figure, using his wits and magic to protect and guide them. This would change the way Asgardians are perceived in the MCU. Instead of being a broken and defeated people, they could become a force to be reckoned with under Loki's leadership.