They might get angry if the fanfiction shows the heroes in a very positive light and the villains as weak or stupid. They have their pride and don't like to be made fun of or belittled, even in fan - made stories.
Some characters might be amused. For example, Hiccup, being the open - minded and curious one, could find it interesting to see how fans imagine different scenarios. He might even get some new ideas for his own adventures.
The characters in 'httyd' would likely have complex reactions to the future in the fanfiction. Hiccup, for example, has always been a forward - thinking character. He would likely be intrigued by the possibilities the future holds, whether it's in terms of dragon - human relations or new inventions. However, he would also be concerned about protecting his tribe and the dragons. Astrid would be more practical. She would assess the potential threats and benefits. The dragons themselves, such as Toothless, would react based on their bond with their human counterparts. If they sense that Hiccup is positive about the future, they might be more open to it, but if there are signs of danger, they would be on high alert.
They might think it's a strange and fascinating alternate view of the world they know. They could be amused by how fans re - imagine the events and characters from HTTYD 1. Maybe they would be a bit jealous if the fanfiction makes the heroes seem even more heroic than in the original movie.
Some characters might be amused. For example, Hiccup could find it interesting to see different interpretations of his adventures in HTTYD 2. He might laugh at the creative liberties taken in the fanfiction.
They may laugh. If the fanfiction contains some humorous scenarios or dialogues that are well - written. For instance, if there are some comical interactions between the dragons and the riders that are different from what's in the movie.
Some characters might laugh at the creative and sometimes out - of - the - box ideas in the fanfiction. For example, if there's a fanfic where a dragon can talk in a very strange accent.
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.
She might be initially scared but quickly regain her composure. Uraraka is a brave character. She would likely start looking for ways to escape, using her zero - gravity quirk to her advantage, like floating up to vents or disabling the villains' weapons if she can.
Shigaraki would likely be disgusted if the fanfic made him seem weak or less of a threat. He'd probably scratch at his neck in irritation. Dabi would be dismissive. He'd think fanfics are just a waste of time and not worthy of his attention. Toga, though, might be intrigued. If the fanfic had a lot of blood and gore in it, or if it focused on her relationships in an interesting way, she could be really into it.