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.
Probably the younger or past versions of the members. They would be seeing all the things they have achieved and how they have changed. It would be like looking into a crystal ball and seeing a very successful future version of themselves.
In such a fanfic, Dumbledore might be astonished by how much Harry has grown. Maybe Harry has new magical abilities that Dumbledore had not foreseen. He could share his future experiences with Dumbledore, like how the wizarding world has changed in the years to come. This could lead to Dumbledore making different decisions in the present to better prepare for the future.
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.
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.
In this fanfic, neither might be more dominant. They could be equal partners. Harry Potter's immortality gives him the ability to endure many challenges, and his magic is a great asset. However, the Doctor has his own set of skills like being able to quickly analyze complex situations and having access to a wide range of alien technology. They would probably complement each other rather than one being dominant over the other. For example, when facing a threat that is both magical and technological, they would need to work together, with Harry using his magic to deal with the magical aspects and the Doctor using his technology to handle the technological parts.
It's really hard to say. Harry has his powerful magic like the Patronus charm and powerful offensive spells. But Luke has the Force which allows him to do incredible things like move objects with his mind. It could depend on the situation. In a magical battle, Harry might have the upper hand, but in a fight that requires physical strength and precognition, Luke could be more powerful.
Hulk could be the most surprised. He doesn't always pay attention to the subtleties of character growth. But seeing Peter, who was once a small and somewhat inexperienced hero, now be this confident and powerful figure from the future would really catch him off - guard. He might even be a bit intimidated at first by the new - found strength and presence of future Peter.
If we consider emotional dominance, Itachi might be more dominant at first as he has always been in control of his emotions and has a lot of secrets that could shock Sasuke. But if future Sasuke has overcome his emotional turmoil and has a clear goal in mind, he could turn the tables. In a physical or power - based sense, it could go either way depending on how the author of the fanfiction has developed their respective powers and skills in the future scenario.
It really depends on the situation. If they are in the wizarding world, Harry Potter would likely be more dominant as he knows the ins and outs of magic and the wizarding society. He can use spells to his advantage and has a deep understanding of the magical threats. But if they are in Oliver Queen's world, in Star City, Oliver would be more in control. He knows the city, has his team, and his combat skills are more useful in a non - magical urban environment.
In some fanfics, if Dumbledore obliviates Harry, it could lead to a very different story. Harry might lose his memories of Voldemort, his friends, and his magical adventures. This could cause chaos as he tries to figure out who he is without his past knowledge. It could also lead to new relationships and character developments as he starts from scratch, perhaps even changing the course of the wizarding world's battle against the Dark Arts.