I think Steven and Zim would be the most interesting pair. Steven's kind - hearted and positive nature contrasted with Zim's evil and self - centered personality would create a lot of comical and tense moments.
Definitely Pearl and Dib. Pearl is so elegant and intelligent, while Dib is a bit of a crazy conspiracy theorist. Pearl could be teaching Dib about the gems and their history, while Dib would be trying to convince Pearl about the existence of real aliens like Zim. Their interactions would be full of misunderstandings and some really funny exchanges.
Well, it could be really wild. Maybe Steven could use his gem powers to try and stop Zim's crazy plans for world domination. Zim, on the other hand, would probably be super confused by Steven's powers and the whole concept of gems.
Zim and Bender would be a really interesting interaction. Zim is this over - confident alien bent on world domination, while Bender is a self - centered, kleptomaniac robot. They could start off by trying to out - do each other in terms of causing chaos or stealing things. GIR and Fry could also be a fun pair. Fry's simple - mindedness would match well with GIR's random and silly behavior. They could get into all sorts of comical situations together, like accidentally starting a food fight in the Planet Express cafeteria.
Steven himself would be very interesting. His kind - hearted nature and unique powers would stand out among the Avengers. He could bring a new perspective to the team.
I think it would be Ben. His ability to transform into various aliens brings a lot of possibilities. He can be a tough fighter like Rath or a strategic thinker like Grey Matter. In the crossover, seeing how he interacts with the Gems and Steven would be really fascinating.
Ruby and Zim could be an interesting pairing. Ruby is young and full of energy and optimism, while Zim is completely delusional and self - centered. Their interactions would be full of misunderstandings and comical moments as Ruby tries to understand Zim's alien ways and Zim just sees Ruby as another obstacle in his plan to conquer Earth.
Sakura and Pearl could also have an interesting dynamic. Sakura is a strong - willed kunoichi who has worked hard to become a great healer and fighter. Pearl is elegant and highly skilled in combat. They could exchange their knowledge of combat techniques and healing methods. Pearl could teach Sakura some of the more refined Gem - style fighting moves, and Sakura could show Pearl how to use her medical skills in more practical and efficient ways during a fight.
Gir could also be a great focus. His love for food and randomness could add a really fun element. Imagine Gir befriending the Powerpuff Girls and getting them into all sorts of silly adventures, while Zim is fuming in the background because Gir is not helping with his evil plans.
Definitely Steven and Dipper. Steven is so open - hearted and has a positive outlook, while Dipper is more skeptical and curious in a different way. Their different personalities could lead to some really interesting exchanges as they try to understand each other's worlds.
Enid from OK KO and Pearl from Steven Universe. Enid is a bit of a cool, laid - back character with her own brand of strength, and Pearl is a very refined and skilled gem. They could have a great dynamic, like Enid teaching Pearl some modern - day Earth things, and Pearl showing Enid some of her elegant combat moves.
Definitely Dipper and Pearl. Dipper is always eager to learn about the unknown and Pearl is full of knowledge about Gem history and technology. Their conversations could be really interesting as they share their insights on different mysteries.