Sasuke and Kylo Ren could be interesting characters to interact. Both have a dark side to them, and it would be fascinating to see how they either clash or find some common ground. Maybe Sasuke would see Kylo Ren's struggle with the dark side and try to use his own experiences to help or hinder him, depending on the story's direction.
Naruto and Rey would be likely to interact. Naruto's positive and determined nature would complement Rey's own strong will. They could exchange knowledge about their respective powers, with Naruto showing Rey how to control her chakra (if she had it) and Rey teaching Naruto about the Force.
Sasuke and Magneto. Both are complex characters with a bit of a dark side. They could either become enemies as their goals might clash. Sasuke is on a journey to gain power for revenge, and Magneto wants to protect mutants but sometimes uses extreme methods. Or they could form an unlikely alliance, learning from each other's determination and power - seeking motives.
Naruto and Dawn are the obvious ones. Since it's a 'naruto x dawn pokemon fanfiction', they would likely be at the center of the interactions. They could start off as strangers and gradually learn about each other's worlds.
Naruto and Hiro are likely to interact. Naruto's enthusiasm and Hiro's intelligence would create an interesting dynamic. They could both inspire each other in different ways, like Naruto inspiring Hiro to be more bold and Hiro teaching Naruto about science and technology.
Iron Man is another candidate. Tony Stark's technology and Naruto's ninja techniques could be a great contrast. They could learn from each other. Stark might be interested in Naruto's chakra - based powers and try to replicate them in some way, while Naruto could be amazed by Stark's high - tech gadgets.
Definitely Naruto and the Punisher first. Naruto would be intrigued by the Punisher's methods and would try to understand his motives. It's also possible that Sakura could interact with the Punisher. She's a strong - willed character, and she might try to either stop the Punisher if she thinks his actions are too extreme or help him if she sees the good in his goals. And Jiraiya might also be a character who could cross paths with the Punisher. Jiraiya's worldliness and his own sense of right and wrong could lead to some deep discussions between them.
I think Naruto and Maz Kanata would be really interesting. Maz is this wise old being who has seen a lot. Naruto could learn a great deal from her about the ways of the Star Wars universe, and in return, he could show her some of his ninja techniques. They could exchange stories about their different worlds and the powers that exist within them.
Sasuke could also have an interesting interaction with one of the goddesses. Given Sasuke's complex personality and his search for power, a goddess might try to guide him in a different direction. Maybe a goddess could show him that there are other ways to gain strength aside from his usual methods, and Sasuke could in turn show the goddess the depth of human emotions and the consequences of a troubled past.
Definitely the Teen Titans. Robin would be interested in Naruto's strategic mind and combat skills. Starfire might be fascinated by Naruto's unique culture. Beast Boy and Naruto could bond over their fun - loving natures. And Cyborg would be intrigued by Naruto's chakra - based abilities compared to his technological ones.
Naruto and Ruby are very likely to interact. Ruby is the main character in RWBY, and Naruto being the central figure in his own story, their paths would surely cross. Ruby's enthusiasm for combat and her leadership qualities could make for an interesting dynamic with Naruto's determination and his own brand of leadership. Also, Weiss could interact with Naruto. Given Weiss's strict upbringing and her proficiency in combat, her reaction to Naruto's unorthodox ninja techniques would be fascinating.
Sakura from Naruto might interact with Louise from Familar of Zero. Both are strong - willed female characters. They could start off as rivals, competing in areas like magic vs medical ninjutsu, but then gradually become friends and learn from each other's strengths.