Another interesting interaction would be between Master Chief and Emile. Emile is very much a front - line fighter with his own unique combat style. Master Chief, being a super - soldier, would have his own way of fighting. Emile might be a bit in awe of Master Chief's abilities at first, but then they could have some intense sparring sessions where they learn from each other's combat techniques and develop a mutual respect.
I think Kakashi's interactions with his younger self would be really cool. He could see how much he has changed over the years and maybe give some advice to his younger self. Also, the interaction between Sakura and Rin. Rin could be like an older sister figure to Sakura, teaching her more about being a kunoichi and sharing her experiences in love and friendship, especially considering Rin's complex relationship with Kakashi and Obito.
Maybe in the fanfiction, Master Chief is sent to retrieve some crucial data that Noble Team also has a lead on. Noble Team is initially suspicious of Master Chief as he is an outsider. However, as they start working together, they come to respect his skills. Master Chief, in turn, is impressed by Noble Team's camaraderie. They face many challenges together, like navigating through a dangerous Forerunner structure filled with traps while being hunted by Covenant Elites.
A new alien species could be the main antagonist. This species could have technology that is completely unknown to both Noble Six and Master Chief. They would have to quickly learn about the new enemy's weaknesses while also trying to survive their initial attacks. This would test their adaptability and teamwork skills.
Definitely Superboy and Wolverine. Wolverine's gruff and experienced nature against Superboy's more idealistic and young hero self would make for some great dialogue and action scenes.
Definitely Naruto and the Little Sisters. Naruto has a soft spot for those in need, and the Little Sisters are in a very vulnerable position. He would probably be very protective of them, and the contrast between his energetic and positive personality and their rather timid and strange existence would be fascinating.
Definitely Sans and Jevil. Sans' laid - back yet perceptive nature combined with Jevil's chaotic and unpredictable personality would make for some really interesting exchanges. Sans might try to understand Jevil's view of the world, which is so different from his own in Undertale.
The interaction between Naruto and Rukia could be great. Naruto's exuberance and positive attitude could contrast with Rukia's more serious and stoic nature. They could bond over their loyalty to their friends. Maybe Naruto could make Rukia laugh with his silly antics, and Rukia could teach Naruto some of the more refined aspects of combat from the Soul Society.
I think Negi and Iron Man would have great interactions. Negi is a young wizard full of potential, and Iron Man is a genius with his high - tech suits. They could probably learn from each other, like Negi learning about technology from Iron Man, and Iron Man getting inspired by Negi's magic for new suit designs.
I think Kakashi's interaction with Minato would be very interesting. Kakashi was Minato's student. Meeting his sensei again, especially with Team 7 in tow, would bring back a lot of memories. Kakashi could show Minato how he has grown and passed on Minato's teachings. And Minato could give Kakashi some new insights based on his own experiences.
Supergirl would be really interesting. Her alien origin and her super strength, along with her ability to fly, would make her stand out. She could bring a new dynamic to Team Flash with her different set of powers and her more idealistic view of heroism, which might contrast with some of the more street - level concerns of Team Flash.