I think an unexpected pair would be Harley Quinn and Martian Manhunter. Harley's chaotic and unpredictable nature combined with Martian Manhunter's powerful and stoic presence could create some really interesting dynamics. Maybe Harley gets into some trouble on Mars and Martian Manhunter has to deal with her while also uncovering a bigger threat to the planet.
Another unexpected pair could be Constantine and Supergirl. Constantine is a dark and gritty character who deals with the occult, while Supergirl is a symbol of hope and light. But if there was a situation where a dark magic was corrupting the people of Metropolis and only Supergirl's strength combined with Constantine's magic knowledge could stop it, that would make for an exciting crossover.
Harley Quinn and Deadpool would be an extremely unexpected pair. Harley's chaotic and unpredictable nature combined with Deadpool's fourth - wall - breaking and equally chaotic personality would make for a really wild and hilarious fanfiction. They could get into all sorts of misadventures while trying to rob a bank or take on a super - villain just for the fun of it.
Gohan and Wonder Woman would be an interesting pair. Wonder Woman's combat skills and her connection to the gods could be a great match for Gohan's Saiyan powers. They could learn from each other's fighting styles and cultures.
I think Spider - Man and Harley Quinn could be a really interesting pair. Harley's chaotic nature and unpredictable behavior would mix well with Spider - Man's sense of responsibility. They could start off as unlikely allies, with Harley initially trying to play tricks on Spider - Man but then realizing they have a common enemy and working together in a really unique way.
I think Squidward from Nicktoons and Courage the Cowardly Dog from Cartoon Network would be quite unexpected. Squidward is always so grumpy and pessimistic, while Courage is, well, cowardly but also very kind - hearted. Their interactions would be really strange and comical.
Plastic Man. Imagine Wolverine's no - nonsense attitude combined with Plastic Man's goofy and elastic nature. They would be a very odd couple. Wolverine might be frustrated by Plastic Man's antics at first, but then they could find that their abilities complement each other well in a fight. For example, Plastic Man could wrap around Wolverine to protect him while Wolverine attacks the enemy with his claws.
I think Naruto and Green Arrow would be an interesting pair. Naruto's brash and energetic nature would contrast with Green Arrow's more serious and calculated demeanor. They could learn from each other's combat styles. Naruto could show Green Arrow some acrobatic moves inspired by his ninja training, and Green Arrow could teach Naruto how to be more precise with long - range attacks using his arrows.
I think Naruto and Batman would be an interesting pair. Naruto is all about his big - hearted, energetic ninja ways, while Batman is the brooding, strategic detective. They could learn a lot from each other. Naruto could teach Batman about the importance of believing in oneself and having unwavering determination, and Batman could teach Naruto about strategic planning and using the environment to his advantage.
Another unexpected pairing would be Asura and the Flash. The Flash is so fast and relies on his speed and quick thinking, while Asura is more about raw power. The Flash could try to outmaneuver Asura, but Asura's power might be too much. However, if they could find a way to work together, they could be a very effective team. For example, the Flash could lead enemies into Asura's path for him to smash.
Spiderman and Batman would be really interesting. They are both intelligent and resourceful. Batman has his gadgets and detective skills, while Spiderman has his super - strength and web - slinging. They could learn a lot from each other.
Wonder Woman is another great choice. Her strong moral code and powerful abilities would be an interesting counterpoint to Deadpool. He might be in awe of her at first, and then start trying to crack jokes and get on her nerves, but they could also form an unlikely friendship as they fight together against a common enemy.