Source: cbr.com
1. The Celestials
Okay I mean we kinda got one of them a little bit in Guardians of the Galaxy.
And ancient cosmic beings like Ego have been dubbed as “Celestials†in the films. But you know what I mean. I mean the big friggin’ Kirby knights that went to war with the Eternals time and time again. The ones that just featured in the most recent arc of The Avengers. I’d love to get a big boy like Eson the Searcher in on the Avengers 4 fun but odds are there’s no place for him.
Again, Thanos kind of needs to be the most powerful figure in the movie to have any sense of threat and that won’t be possible if there are godlike beings strolling around doing whatever they want. All hanging out with the Machine Man and stuff. Calling him a s**t robot or whatever they get up to.
It’d be a fun old time.

