Sakura might be the most surprised. She has always been very close to Naruto, and seeing him as a powerful future version would be quite a shock. She might be amazed at how he has developed his skills and also how he has changed as a person.
I think Sasuke could also be extremely surprised. Given his complex relationship with Naruto, seeing a future Naruto would make him re - evaluate their past and future interactions. He would be taken aback by Naruto's growth, especially if Naruto has achieved things that Sasuke hadn't even considered possible.
Honestly, it's hard to say. Dumbledore would be amazed at Harry's future self, but Harry would also be taken aback by seeing Dumbledore in a different time. It could depend on the circumstances of their meeting. If Harry comes back to a time when he thought Dumbledore was dead, then he would be extremely shocked. On the other hand, if Dumbledore has been expecting some sort of time - traveling encounter, he might be less surprised than Harry.
Sasuke would also be a likely candidate. His journey is filled with so many twists and turns. His future self could show him an alternate path or confirm that the path he is on is the right one. Maybe he becomes more at peace with his past and his clan.
The relationship between Naruto and Sasuke could become more complex. If Sasuke's future self has accomplished great things but at a cost, Naruto might question his own ideas of success. For Sakura, seeing her future self might make her more assertive in her relationship with the boys, especially if she has become a very respected ninja.
Well, one possibility is that future Naruto has some sort of warning about a great danger that is coming to their present time. So, he travels back to meet Team 7 to prepare them. Team 7 would then have to deal with the knowledge that they are somehow crucial in preventing this future threat. And of course, there would be a lot of emotional moments as they see what Naruto has become.
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.
It could be the newer protagonists who are more surprised. For instance, if a protagonist from a more recent game meets Ash, who is like a legend in the Pokemon world. They would be in awe of his adventures and his reputation, while Ash might be more used to strange encounters compared to them.
Well, in this fanfiction scenario, Team Minato could initially be shocked to see Naruto from the future. Naruto might introduce them to new ninja techniques that he has developed over the years. And there could be a lot of emotional moments as Naruto reflects on his relationship with his former sensei, Minato. Also, they could team up to face a new, powerful enemy that threatens the future of the ninja world, with Naruto guiding them using his future knowledge.
I think Uraraka would be very excited. She has always been a big supporter of Deku. Meeting Future Deku would give her a chance to see how far he has come, and she might also get some inspiration for her own hero journey. Plus, she's a friendly and emotional character, so she'd likely be thrilled at the opportunity.
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.
I think there would be a mix of emotions. Naruto would feel a connection right away, but the younger Team 7 might be a bit confused. They might not understand why this older Naruto is so interested in them. But as time goes on, they would start to trust him. Naruto could play games with them to break the ice, like ninja tag or something. And he would be constantly trying to boost their confidence, especially Sasuke who has a lot of pride.