What are some interesting ideas for a Ben 10 x Avatar fanfic?

One idea could be a crossover where Ben 10's Omnitrix malfunctions near Avatar Aang's world. Ben and Aang team up to face a new threat that is causing chaos in both their realms. Maybe some of Ben's alien forms have unexpected interactions with the bending abilities in the Avatar world.

One idea could be that Ben Tennyson's Omnitrix malfunctions while he's in the Avatar world. So, instead of transforming into his usual aliens, he starts taking on the forms of Avatar creatures. For example, he might turn into a flying bison or a waterbender - like spirit. This would create all kinds of chaos and new adventures as he tries to figure out how to control these new forms and also deal with the political and elemental challenges of the Avatar world.

One idea could be a story where Ben and Kevin have to team up against a new, powerful alien threat that neither of them can face alone. They have to combine their powers and skills in unique ways.

Another interesting plot could be that some of Ben's alien forms are mistaken for new mutants in the Marvel Universe. He then has to prove that he's not a threat while also helping the X - Men deal with a common enemy that is interested in the genetic makeup of both mutants and Ben's alien forms.

Perhaps a fanfic where Ben and Rook accidentally swap abilities. Ben has to deal with Rook's weaponry and combat skills, while Rook tries to control the Omnitrix. It would be full of comical moments as they struggle to adapt, but also a chance for them to learn more about each other's strengths and weaknesses.

One idea could be exploring Alien X's internal conflict between Bellicus and Serena in a new situation. For example, when faced with a moral dilemma on a planet where two species are at war and both have valid reasons for their actions. Another plot could be Alien X having to deal with a powerful new enemy that can somehow disrupt his omnipotent powers. Maybe this enemy has the ability to split Bellicus and Serena's consciousness further, causing chaos within Alien X.

One interesting idea could be exploring an alternate universe where Ben's Omnitrix has different aliens with unique powers. For example, aliens that can manipulate time in ways not seen in the original series. Another idea is to focus on a story where Ben has to team up with his enemies to face a greater threat. This would create a lot of interesting character dynamics.

Maybe the Avatar, in his journey to master all the elements, travels to the Naruto world. He could learn some ninja techniques and incorporate them into his fighting style. The Avatar could also teach the ninja about the power of bending, which could lead to some really unique team - up strategies among the characters.

A really interesting plot could involve a time - traveling aspect. Ben and Julie accidentally travel back in time to when Ben first got the Omnitrix. They have to be careful not to disrupt the timeline while also trying to find a way back to their own time. Along the way, they could meet younger versions of characters they know and have some really fun and emotional interactions. This could also lead to Ben learning some important lessons about his powers from his past self.

Definitely Ben Tennyson himself. He has a whole range of alien forms and abilities, and seeing how he would adapt to the Avatar world would be really cool. For instance, how would he use Four Arms in a fight against earthbenders or how would he use XLR8's speed in a chase through the air temples.