One possibility could be that Naruto is somehow transported to the Avengers' world during the Age of Ultron. He might initially be seen as a threat due to his strange powers. But then he could prove his worth by using his ninja skills to fight Ultron's minions. His shadow clone jutsu, for example, could be very useful in confusing the robotic enemies.
Well, it could be really wild. Maybe Naruto somehow gets transported to the Marvel universe and teams up with the Avengers against Ultron. He'd bring his ninja skills like shadow clones and rasengan, and the Avengers would be both confused and impressed.
Some niche fanfiction communities on Reddit or Discord might also have Naruto is Ultron fanfictions. You can join relevant groups and ask if anyone has come across such a story. But be sure to follow the group rules when you're looking around.
Naruto could also have some interesting interactions with Black Widow. She is a master of espionage and Naruto has his own ninja skills. They could share their knowledge about stealth and infiltration. Maybe they could come up with a plan to infiltrate Ultron's main base using a combination of Naruto's shadow clone jutsu and Black Widow's spy techniques. It would be a very exciting part of the fanfiction.
Spider - Man could use his agility. He could quickly dodge Ultron's attacks and find a weak spot in Ultron's armor. Since he's so fast and nimble, he could get in close and plant some sort of disabling device he made with his scientific knowledge.
In some fanfictions, Ultron might team up with one of Spider - Man's villains, like the Green Goblin. They could create a plan to take over New York. Spider - Man would then have to face this powerful alliance. He might seek help from other superheroes he's associated with, like Iron Man or Daredevil, to combat this new threat.
Another way Peter could be of help is with the setting. He could describe in detail how New York City (or wherever the story is set) looks during the Age of Ultron. With his knowledge of the city streets and rooftops, he could make the battle scenes more vivid and realistic.
It can also be frustrating at times. Some fanfictions lack the proper understanding of the movie's lore. They might introduce concepts that don't fit well with the established Marvel Cinematic Universe. But on the positive side, many fanfictions are a labor of love. Authors pour their passion for the movie into their writing, and that can really shine through, especially when they capture the essence of the characters as we know them from the movie.
Well, one reaction could be excitement. Fanfictions often explore different aspects of the characters and storylines that might not have been fully delved into in the movie. For example, they might focus on the relationships between the Avengers in more depth, like the budding romance between Black Widow and Hulk. It can be really interesting to see how different authors interpret the characters' emotions and motives.
Well, in a lot of fanfiction, the idea is that Tony's creation of Ultron was a complex situation. He was acting out of fear for the safety of the Earth. The Avengers had faced many threats, and he thought an AI like Ultron could be a preemptive defense. So, the fanfiction authors don't blame him as they understand his motivation and the unforeseen consequences that came with his experiment.