There's a chance that side characters get more focus too. Maybe characters like Rhodey or Nebula could have more in - depth character development as they react to the events of Endgame while being watched by the Avengers in the fanfiction.
Captain America is also a key focus. His leadership qualities are highlighted. He could be seen rallying the other Avengers as they watch the trailer, giving inspiring speeches about not giving up and fighting for the universe.
Some characters might be amused. For example, Iron Man could be like 'Well, this is an interesting take on our story.' He might find the creative interpretations of his character in the fanfiction either entertaining or a bit off - mark.
One highly regarded story is 'The New Beginning' which explores what happens after the events of Endgame in a really unique way. It delves deep into the characters' emotions and how they cope with the new world they're in. Another great one is 'Beyond the Snap' which focuses on the alternate timelines that could have been created during the events of the movie. It's really interesting to see how the author plays with the concepts from the movie.
Another option could be Tumblr. There are many Tumblr blogs dedicated to Marvel and Avengers in particular. While it's not as organized as the dedicated fanfiction platforms, with some searching, you can come across some interesting Avengers Endgame fan - written stories.
Spider - Man, being the youngest of the group, would be really excited. He would love seeing all the different versions of the Avengers' story. He might even get some inspiration from the fanfiction for his own heroic deeds. He could exclaim 'This is so cool! There are so many ways our story can be told!'
You can try websites like Archive of Our Own (AO3). It has a large collection of fanfiction on various topics, including Avengers watching Avengers Endgame. There are also some fanfiction sections on dedicated superhero forums where fans share their creative works.
A really cool plot idea could be that the Avengers are watching Endgame in a sort of 'alternate reality cinema' where the events in the movie start to bleed into their real world. So they have to stop the movie from fully playing out to prevent chaos in their own universe. This would involve a lot of action and strategic thinking as they try to stop things like Thanos from emerging from the screen while also trying to understand the significance of what they're seeing in the movie.
Thor is very popular in post - Avengers Endgame fanfiction. His journey of self - discovery after Endgame, from being out of shape and depressed to finding a new path, is a rich area for fanfic writers. Wanda Maximoff is also a favorite. Her power and the emotional turmoil she went through in Endgame, especially with Vision's death, are often delved into. Additionally, Clint Barton, with his complex past as Ronin and his family life, is a character that many fanfic authors like to focus on in the post - Endgame world.
Well, one interesting thing could be the characters' reactions. They might have different emotional responses seeing the events of Endgame unfold in the fanfiction compared to the movie. For example, Iron Man could show more internal struggle as he witnesses his sacrifice again.