There are a lot of characters who are going to need to be juggled around when Avengers: Infinity War arrives in May, but there's one in particular who director Anthony Russo is most excited about. One half of the Marvel directing duo says that Thor's story in the forthcoming film is the one he's most looking forward to because the events of Thor: Ragnarok have sent the character down the most interesting path, which the massive team up will continue. According to Russo...
I'm going to pick Thor because Thor, we're picking up his story from the end of Thor: Ragnarok and at the end of that film as any fan would know his home planet of Asgard is destroyed, and so the character is in new territory so to speak, because his past has been torn away from him to a degree.
It's certainly true that Thor went through a lot over the course of Thor: Ragnarok. Anthony Russo's comments to Comicbook.com, that his past has been torn away to a degree, may be an understatement. Not only is Asgard gone, but a lot of what Thor thought he knew about his father and his own past turned out to be less than accurate. Thor needs to find a new identity now because the old one is gone. He is the leader of the Asgardians, what's left of them, although, based on what we've seen in the first trailer for Infinity War, it's possible that things aren't going to start out that well for him in that regard.
That isn't to say that Avengers: Infinity War doesn't see other characters in very different places. The Avengers, as an organization is all but disbanded and several of their former members would appear to be fugitives after Captain America broke them out of jail. Though we still have an idea what sort of things to expect from them. Steve Rogers will be no less Captain America, even if he's missing the uniform and has grown a beard. Thor is a bit different as he's in a position where he will likely need to do a bit of soul searching and figure out just what sort of person he is now.
Anthony Russo also confirmed that Avengers: Infinity War will pick up right where Thor: Ragnarok left off, so there won't be time off screen for Thor to have figured out all the answers. The audience will follow Thor as he enters into this new territory for the first time.
While we expect Avengers: Infinity War, and the follow-up Avengers 4 to be the end of the road for some characters, that doesn't mean they will cease to evolve and change, even if their story is coming to an end. Whether or not that's the case for Thor, we'll have to wait and see.