Exactly. He is very much the most 1930's comic book-y character there is in this show, and pretty much the representation of that type of hero archetype. If we go a bit by their personalities and morality compared to the Justice League:

Actually when we first saw Rex disappear I thought he was a hologram since, in the season 1 finale when they first get back to 2016, Rip had used a similar technique to say goodbye to the group.