Batman would be really interesting. Korra, being used to a world with clear good and bad, could be intrigued by Batman's morally gray methods. Their interaction could involve Korra trying to understand why he doesn't use more lethal force against his enemies, and Batman being fascinated by her bending abilities and how she uses them for both combat and peaceful purposes.
The Flash would also be an exciting character for Korra to meet. Korra, who has her own speed in combat through her bending, could be amazed by the Flash's super - speed. They could have a race where Korra uses her air bending to enhance her speed, and the Flash discovers that there are other ways to move quickly besides his super - power. Their interactions could be full of humor and friendly competition as they learn about each other's abilities.
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.
Superman would be really interesting. Their powers are quite different. Superman is an alien with a wide range of powers like flight, super - strength, heat vision etc. The Hulk, on the other hand, is a being of pure rage with ever - increasing strength. Their encounter could be a clash of ideologies as well. Superman stands for truth, justice and the American way, while the Hulk is often just a force of destruction when enraged. It would be fascinating to see how Superman tries to calm the Hulk down or how the Hulk reacts to Superman's attempts at peacekeeping.
Superman would be really interesting. Ichigo, coming from a world of spiritual powers, would be in awe of Superman's physical strength. And Superman would be curious about Ichigo's ability to see and interact with souls. Their different power sets and moral compasses could lead to some great character - building moments. For example, Ichigo might learn about the importance of using power responsibly in a more global sense from Superman.
A possible story could be Korra getting involved in a conflict between the different factions in the DC Universe, like the Amazons and Atlantis. Her ability to understand different cultures and her diplomatic skills, which she developed in her own world, could be used to ease the tensions between them. She could also use her earth bending to help repair the damages in Atlantis caused by a recent battle, and in return, the Atlanteans could offer her some knowledge about their advanced technology which could be useful for her in future battles in her own world.
I think Hermione and Superman would be an interesting pair. Hermione is all about knowledge and learning, and Superman, with his alien origin and super - intelligence, could share a lot with her. They could exchange ideas about their respective worlds, and Hermione might even find a way to use magic to enhance Superman's powers or help him in some way.
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.
Definitely The Flash. Their powers are quite different. The Flash's super - speed could be an amazing contrast to Deku's more physical - based quirk. Deku could learn about time - related concepts from The Flash, and they could have an interesting dynamic when it comes to chasing villains.
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.
Itachi and Luffy would be really interesting. Luffy is so carefree and straightforward, while Itachi is complex and burdened. Their interactions would be full of contrasts. Luffy might try to cheer Itachi up or get him to loosen up, while Itachi could be impressed by Luffy's unwavering determination.