Well, in this fanfiction, it could be that Spiderman uses his agility and web - slinging skills to outmaneuver the enemy. Maybe he creates a huge web shield to protect the Avengers from a powerful blast. His spider - sense could also alert him to hidden dangers that the Avengers might not notice, allowing him to save them at the crucial moment.
A possible plot twist could be that Spiderman is actually from an alternate dimension where he has different powers. And these powers are the key to saving the Avengers. For example, he might be able to time - travel in this dimension and go back to prevent the event that put the Avengers in danger in the first place.
Perhaps the Avengers are under some sort of mind - control spell. Spiderman, being immune to the spell for some reason, has to figure out how to break it. He might swing around, avoiding attacks from his brainwashed friends, and then find a way to disrupt the source of the mind - control. For example, he could web up a device that was emitting the mind - controlling waves.
The three Avengers could be Iron Man, Captain America and Thor. Iron Man could provide the high - tech gadgets and strategic thinking. Captain America would bring leadership and his combat skills. Thor with his godly powers like lightning and super strength would be a great addition. They would each have different interactions with Spiderman, for example, Iron Man might be like a mentor to him, while Thor could be more of a friendly rival in terms of strength.
One great 'Avengers and Spider - Man fanfiction' is 'The Friendly Neighborhood Avenger'. It combines Spider - Man's street - level heroics with the grandeur of the Avengers. It has an interesting plot where Spider - Man has to teach the Avengers some of his unique ways of dealing with small - scale threats while also learning from them about handling large - scale disasters.
There's also 'Spiderman's Avengers Adventure'. This fanfic delves into what would happen if Spiderman had to lead the Avengers in a crisis situation. It's full of character development, especially for Spiderman as he steps up to the plate. The story has a great balance between his quippy nature and the seriousness of the situation.
It depends on the type of fanfiction. In some darker or more angst - filled fanfictions, it is quite common as it adds drama. However, in more positive or team - building - focused fanfictions, it's not as common. These types of stories usually focus on the Avengers and Spiderman working together and getting along. So, it varies from one type of fanfic to another.
Spiderman might use his agility and web - shooting abilities. He could quickly web up Venom, restraining his movements and preventing him from attacking the Avengers.
The other Avengers would be devastated. Iron Man, for instance, might feel guilty as if he could have done something more to protect Spiderman. He might become more withdrawn and focus even more on creating better technology to prevent such tragedies in the future.