A really interesting aspect could be the technology exchange. The Avengers with their high - tech gear and Ben with his Omnitrix. Maybe they could work together to upgrade their respective technologies. For instance, Tony Stark could help Ben improve the Omnitrix's interface, while Ben could show the Avengers some alien - inspired tech.
In some fanfictions, there might be a plot where the Avengers mistake Ben for a threat at first. But then they realize his good intentions when he helps them fight a common enemy. This adds an element of misunderstanding and then friendship, which is quite common and engaging in crossovers.
In some fanfictions, the technology in Ben 10's world might be combined with Stark's technology in the Avengers. Maybe Ben's Omnitrix could be enhanced by Stark's knowledge, creating a more powerful device that helps them in a battle against an alien invasion. This would involve a lot of scientific discussions and teamwork between Ben and the Avengers, especially Tony Stark.
One interesting crossover could be Ben using his alien forms to help the Avengers in combat. For example, Four Arms could provide extra strength in a fight against a powerful enemy like Thanos. Another could be Heatblast teaming up with the Human Torch to create an even more intense heat-based attack.
One interesting crossover could be Ben using his alien forms to help Batman fight Gotham's villains in a more unique way. For example, Heatblast could be used to deal with Mr. Freeze in a direct heat - based battle.
One idea could be a crossover with the Powerpuff Girls. Ben could team up with the girls to fight a common enemy that is causing chaos in both their universes. Another could be a crossover with the Teen Titans. Ben's alien forms and the Titans' powers would make for some epic battles and cool team - up moments.
One interesting crossover could be the Flash from Arrowverse meeting Quicksilver from the Avengers. They could have a race to see who is truly the fastest. Another could be Green Arrow teaming up with Hawkeye for an archery - based mission where they share their different techniques and arrow - making skills.
A possible crossover could involve the technology of Kingsman, such as their fancy suits and gadgets, being integrated into the Avengers' gear. The Kingsman's bulletproof suits and high - tech umbrellas could give the Avengers an edge in combat. Also, the different cultures and protocols of the two groups would create some interesting clashes and comical moments as they try to work together.
Crossovers that involve the villains from both universes teaming up are also quite fascinating. For example, Loki from the Avengers and Orochimaru from Naruto joining forces. The heroes then have to come up with a strategy that takes into account the different powers and motives of these two very different villains. It's a great way to create high - stakes situations and see how the heroes from two different universes can work together to overcome a common foe.
The cultural clash is also a really interesting aspect. Kagome comes from a very different cultural background than the modern - day Avengers. So seeing how she reacts to things like Stark's flamboyant lifestyle or Captain America's old - fashioned values can make for some great reading. In some fanfictions, this clash leads to humorous situations as well as deep character growth for both Kagome and the Avengers.
One interesting crossover is when Superman's code of ethics clashes with the Avengers' more flexible approach. It creates a lot of drama and character development. For instance, in some stories, Superman has to decide whether to follow the Avengers' plan which might involve a bit of collateral damage, something he's not used to in his own world.
The crossover where Batman takes on the role of a strategist for the Avengers during a major battle against an alien invasion. His tactical mind helps the Avengers in a way they've never experienced before.