One idea could be that Spider - Man has to use his unique abilities to solve a mystery within the Avengers' headquarters. Maybe there are some strange energy signatures that only his spider - sense can detect.
A great plot could involve Spider - Man being the key to uniting a fractured Avengers team. He might use his charm and street - smart nature to bring together members who have had differences. For example, he could help Iron Man and Captain America see eye - eye again after some sort of misunderstanding. His relatable nature as a young hero could be the bridge between the more experienced and sometimes stubborn Avengers members.
One idea could be that Spider - Man has to use his unique street - level skills to help the Avengers in a mission where they are facing a villain who can manipulate technology in a city. His agility and quick thinking can give the Avengers an edge in the narrow alleys and on top of skyscrapers.
Maybe in the fanfiction, Spider - Man discovers a secret connection between his powers and an ancient Asgardian artifact. The Avengers, especially Thor, would be intrigued. They then embark on a journey to figure out how this connection could either save or endanger the world. Spider - Man would have to balance his normal life and this new discovery with the Avengers.
One idea could be Spider - Man joining the Avengers on a mission to a far - off planet. He uses his agility and quick thinking to help the team out of tricky situations. Another could be a story where Spider - Man has to prove himself to the Avengers in a training exercise set up by Iron Man.
One idea could be Agent Venom having to team up with Spider - Man to take on a new super - villain who has the ability to control technology. They start off distrusting each other because of their different methods, but as the story progresses, they learn to work together. Another plot could involve Agent Venom getting infected with a virus that makes him turn on Spider - Man, and Spider - Man has to find a cure while fighting off Agent Venom's attacks. A third idea is that they both discover a secret conspiracy within the superhero community that they have to expose together.
The Vulture would be a great choice. His flight abilities and scavenger - like nature could pose a unique threat to the Avengers. Spider - Man already has a history with him, and it would be interesting to see how the Avengers deal with a villain who is more used to operating on a smaller, street - level scale like the Vulture.
Doctor Octopus could be a great main antagonist. He could upgrade his mechanical arms and team up with other villains. His intelligence and his ability to create complex machines could pose a serious threat to the Avengers and Spider - Man.
One idea could be that Spider - Man uses his agility to outmaneuver an enemy that has the Avengers trapped. For example, he could swing in and steal a key device from the bad guys that's jamming the Avengers' powers.
An exciting story could be when the Avengers are trying to stop a giant alien invasion in New York. Spider - Man swings into action. He uses his webs to tie up the legs of the huge alien creatures, slowing them down. His acrobatic moves as he jumps from one alien to another are amazing. The Avengers watch in admiration as he single - handedly takes on multiple aliens at once. Eventually, they all work together to drive the aliens back into space.
One idea could be that Naruto is somehow transported to the Marvel universe where the Avengers are. He could use his ninja skills, like his shadow clone jutsu, to confuse the villains that the Avengers are facing. Maybe he teams up with Iron Man and they combine their tech and ninjutsu to create some really cool weapons or defenses.
One idea could be a male OC who has the power to manipulate time. He could be from a different dimension where the Avengers failed, and he comes to this universe to prevent the same fate. He might initially be distrusted by the Avengers but gradually prove his worth as he helps them defeat a powerful new enemy that was also a threat in his own dimension.