A really interesting plot twist could be that the symbiote from the Spider - Man universe attaches itself to a major villain in My Hero Academia. This would make the villain even more powerful and unpredictable. The heroes would have to figure out how to deal with this new threat that has a combination of a quirk and the symbiote's abilities.
Maybe there's a plot twist where it's revealed that All Might was secretly in contact with Spider - Man in the past. He learned some of Spider - Man's techniques and incorporated them into his own fighting style. This would change the way fans view All Might's abilities and his backstory, adding a whole new layer of mystery.
A plot twist could be that the Quirk system and Stands are somehow related. Maybe there was an ancient event that split the power into two forms. This would open up a whole new exploration of the lore in both universes. Characters would have to reevaluate their understanding of their own powers and how they interact with those from the other universe.
One interesting plot twist could be when a character from My Hero Academia ends up being a key figure in the Fate Stay Night world's power struggle. Maybe a hero's quirk is actually related to the magic system in Fate Stay Night in a way that no one expected.
The mentor - mentee relationship is quite common. Spider - Man could be a mentor to a young hero in My Hero Academia, teaching them about responsibility and using their powers. Also, the team - up trope is popular. The heroes from both franchises joining forces to take on a big threat, and seeing how their different personalities mesh during the mission.
One interesting crossover could be where Spider - Man's web - slinging abilities are combined with a character from My Hero Academia's quirk in a unique battle scenario. For example, if Midoriya had to learn from Spider - Man how to use his web - slinging in a more strategic way during a joint mission against a powerful villain.
Definitely Midoriya and Peter Parker. Midoriya is all about self - improvement and inheriting power, while Peter has his own journey of learning to use his powers responsibly. They could have great conversations about what it means to be a hero.
One interesting plot twist could be the main character's gamer abilities suddenly evolving in an unexpected way. Maybe they gain a new power that completely changes the way they interact with the world of My Hero Academia. For example, instead of just having enhanced physical stats like in the game, they can now manipulate time briefly, which throws off all their enemies and allies alike.
One interesting plot twist could be a character who was thought to be a minor villain turns out to be a double agent working for the heroes all along. This completely changes the perception of their actions throughout the story.
Perhaps the mask has some sort of hidden power that the main character discovers by accident. For example, it might be able to manipulate time on a small scale, which could be used to turn the tides in a battle or save a life at a crucial moment.
A popular pairing could be Spider - Man and Midoriya. People might like this pairing because they are both the main protagonists in their respective stories and share a lot of similarities in terms of their growth, determination, and their sense of justice.
Well, in some fanfictions, there might be a plot twist where the future that is being watched is actually an alternate and false future created by a powerful villain. This would completely change the characters' understanding of what they need to do to prevent it. Also, perhaps a character who has been in the background suddenly reveals a powerful and unexpected quirk that saves the day.