Well, perhaps the characters start to discuss among themselves about how the fanfiction portrays them. They could be either amused or a bit offended. For example, if a character is depicted as being cowardly in the fanfiction when they see themselves as brave, they would likely have a strong reaction. They might even try to figure out who wrote it and why they were written that way.
In the 'characters watching meet the robinsons fanfic', there could be a scenario where the characters are trying to learn from the positive attitude of the Robinsons. The Robinsons' never - give - up spirit might inspire the watching characters to face their own challenges in their respective stories. Also, the characters might be really entertained by the comical moments in the fanfic, like the goofy antics of some of the robots or the funny misunderstandings between characters in the 'Meet the Robinsons' world.
They could be shocked. Some of the fanfiction might have really wild ideas that they've never thought of.
One interesting scenario could be a character watching the virtual world of Lyoko from the outside, feeling a sense of awe and fear at the same time. They might be amazed by the beauty and danger of it. Another could be a character secretly watching another character's actions in Lyoko to learn more about their capabilities or motives.
One possibility is that they might be amused by the creative interpretations of their own personalities in the fanfic. For example, if Metro Man is watching, he could be laughing at how the fanfic writer made him seem even more heroic or perhaps gave him some comical flaws.
One popular website could be Archive of Our Own (AO3). It has a large collection of fanfiction, including Flash fanfiction. Another option might be FanFiction.net, which has been around for a long time and has a significant amount of Flash - related stories.
Another scenario might be the RWBY characters reacting to different versions of themselves from alternate universes. They could be shocked, intrigued or even a bit envious of the differences in their other selves' abilities, appearances or personalities. This could lead to some self - discovery moments for the characters.
A character like Katniss from The Hunger Games reading a fanfiction where she uses her archery skills in a post - apocalyptic world filled with zombies. She could gain new perspectives on survival and how her skills could be applied in different extreme situations. Fanfiction can offer these unique and thought - provoking scenarios for characters to experience.
One interesting scenario could be a race between Naruto - wolf and Sasuke - wolf to see who is faster and more agile in their wolf forms. Another could be the pack, led by Naruto, having to defend their territory from other wolf packs, with Sakura - wolf using her wits and strength to help. And perhaps a scene where Sasuke - wolf goes off on his own for a while, causing concern among the pack.
One interesting scenario could be when Pikachu reacts to seeing a new type of Pokémon for the first time. It might be both curious and a bit scared.
You can expect to see unique interpretations of the Flash's story. Maybe new character developments that the official show didn't explore. It could also have different takes on the relationships between the Flash and other Arrowverse characters.