Well, I think Sam Winchester and Clark Kent would have a really interesting interaction. Sam is used to dealing with the supernatural and trying to find the good in things that seem evil at first. Clark, with his alien powers, is constantly trying to figure out how to use his abilities for good while hiding his true identity. They could bond over their shared sense of responsibility. Also, Dean Winchester and Lois Lane would be fun to see together. Dean's flirtatious nature and Lois's feisty attitude would lead to some great exchanges. And then there's Castiel and Lionel Luthor. Castiel's angelic presence could either terrify or intrigue Lionel, and their interaction could potentially change Lionel's view of the world in a crossover story.
Definitely Clark Kent and Dean Winchester. Dean has his tough - guy hunter persona, while Clark is the all - American good guy with superpowers. Their different approaches to protecting people would make for some great banter and clashes of ideology. Another interesting interaction would be between Sam Winchester and Lex Luthor. Sam's intelligence and his experience with the supernatural could put him at odds with Lex's brilliant but often morally - grey mind. And Castiel and Chloe Sullivan could also have an interesting dynamic. Castiel's otherworldly nature and Chloe's inquisitive journalist side would lead to some really unique conversations.
Definitely Clark Kent and Oliver Queen. They come from different worlds but share a sense of justice. Their interactions would be fascinating as they learn from each other's methods of fighting crime. Clark could show Oliver the power of his super - abilities, while Oliver could teach Clark some of his stealth and strategic skills.
Definitely Clark Kent and Dean Winchester. Clark with his superpowers and strong moral code, and Dean with his tough - as - nails hunting skills and loyalty. They could have some great banter as they come from such different worlds but find common ground in protecting people. Another interesting pairing could be Sam Winchester and Chloe Sullivan. Sam's intelligence and knowledge of the supernatural could pair well with Chloe's investigative skills.
Definitely Joker and Makoto Yuki. Joker is the leader of the Phantom Thieves, very confident and strategic, while Makoto Yuki is a strong and silent type. Their leadership styles could clash or complement each other.
Definitely the interactions between the two versions of Leonardo. The 2012 Leo is more light - hearted in some ways compared to the very serious 2003 Leo. They could have some great moments of leadership clashes and then learning from each other. For example, the 2003 Leo could teach the 2012 Leo some of his more stoic leadership techniques.
I think the interaction between Joker (from Persona 5) and Yu (from Persona 4) would be really interesting. They are both leaders of their respective groups, so they could exchange leadership strategies and learn from each other. Also, Morgana and Teddie would be hilarious together. Morgana's serious yet sometimes clueless nature and Teddie's over - the - top and comical personality would create some great comedic moments.
Definitely Danny and Dean. Dean is all about hunting monsters and his initial reaction to Danny, a half - ghost, would be very interesting. He might be skeptical at first but then see Danny's potential in fighting the supernatural threats that are a bit out of his usual realm.
Definitely Mario and Sans. Sans' laid - back attitude and his powerful abilities would contrast greatly with Mario's more heroic and straightforward nature. Their conversations would be filled with humor and misunderstandings. For example, Sans might make some jokes about Mario's mustache or his choice of overalls, while Mario would be confused by Sans' skeletal appearance and his knowledge of timelines.
I think the interaction between Ruby and Ben would be really interesting. Ruby is very energetic and has a strong sense of justice. Ben, with his experience of using the Omnitrix to save the day, could share some of his stories with her. They could also have some friendly competitions regarding their combat skills, like who can take down a group of Grimm faster, with Ruby using her Crescent Rose and Ben using one of his alien forms.
One of the most interesting interactions would be between Bayonetta and Hinata. Hinata's shy nature would be a stark contrast to Bayonetta's boldness. Bayonetta could inspire Hinata to be more confident in herself. Also, the interaction between Rock Lee and Bayonetta would be fun. Rock Lee would be eager to prove himself to her in combat, and Bayonetta would be entertained by his enthusiasm and unique fighting style.
Ikaris and Thor would be really interesting. Ikaris has his flight and laser - like eye powers, while Thor has his godly strength and control over lightning. They could have a friendly competition over who can reach a far - off location faster or who can defeat more enemies in a short time. Their different personalities, with Ikaris being more stoic and Thor being more boisterous, would create great banter.