Naruto would be excited. He loves new adventures and ideas, so fanfiction would be like a new set of stories for him. He might even get inspired to try some of the things he reads about in his real life, within the boundaries of his world, of course.
Sakura would probably be a bit more judgmental. She has high standards when it comes to things related to the ninja world. If the fanfiction doesn't match up with her understanding of things like chakra control or ninja ethics, she would be less than impressed.
The MHA characters' reactions could vary widely. For instance, All Might might see the Naruto fanfiction as a great source of inspiration. He could admire the way the characters in Naruto strive for their goals, just like heroes in their own world. Todoroki might be a bit detached but still interested. He'd analyze how the power systems in Naruto compare to quirks in their world. Mineta would probably be more interested in any fan service - like elements if there were any, but that's not a very positive reaction. Overall, it really depends on each character's personality.
A brave character might be more interested in the action - packed parts of the fanfiction. For example, if there are intense chase scenes in the maze, they would be excited and might even try to re - create those scenes in their real 'Maze Runner' world.
Tony Stark's flamboyant and curious personality would make him eager to explore the fanfiction. He'd be interested in the new ideas and concepts it presents. Steve Rogers' more traditional and moral - centered personality might make him a bit critical of any fanfiction that goes against the Avengers' values. Thor, with his fun - loving nature, would probably embrace the fanfiction wholeheartedly.
The extroverted Avengers like Tony Stark would probably take it in stride and even joke about it. He has a sense of humor about things and would likely find the creative ideas in the fanfiction funny. In contrast, Steve Rogers, being more old - fashioned and reserved, might be a bit taken aback. He values privacy and the idea of people creating fictional relationships for them might seem a bit odd to him.
They would probably be shocked. For example, Naruto might be amazed to see how the village develops further. He could be excited to see new generations of ninjas and the peace that his efforts have led to in the future. Sasuke might be more reserved in his reaction, but he would also be interested in seeing if his own actions had a long - term impact on the ninja world.
Some characters might be shocked. For example, Naruto himself. He has always been full of hope for the future and worked hard to build a better world. If he saw a future that was not as positive as he expected, he would be very disappointed at first. But then he would surely try to find a way to change it, because that's his nature.
Ruby's reaction would be one of pure excitement. She'd be like a kid in a candy store, loving all the cool and flashy elements in the fanfiction. Weiss, on the other hand, would approach it with a more academic eye. She'd be analyzing the plot, the character development, and how it all fit together. Blake would be quieter, but she'd be deeply engaged, thinking about how the themes of the fanfiction related to her own life and struggles. Yang would be the life of the party, shouting and getting really pumped up during the high - energy parts of the story.
Some characters might be shocked. For example, Ichigo might be surprised by the future battles and the development of his friends. He could see new powers emerging and might start to train harder in the present to face the future challenges.
Some characters might be amused. For example, Percy could find it really funny to see how fans imagine his adventures in different ways. He might chuckle at the creative liberties the fanfiction writers take.
The Ghostfacers would probably be excited. They are always eager to encounter new elements in the supernatural world, and an angel like Castiel is a huge deal. They might start asking him all sorts of questions right away. Castiel, on the other hand, might be a bit bemused. He's used to more serious situations and these guys with their cameras and loud voices could be a bit much for him at first.