He should have told Meera "A live body and a dead body contain the same number of particles."
shareDefinitely!
Like Dr. Manhattan, he can see backwards in time, and across the continent, and some part of him actually travels across space and time and can affect things in the past. Or maybe doesn't travel per se, but simultaneously exists in both (or all) places and times.
Unlike Dr. Manhattan, he doesn't appear to be able to manipulate matter. But he can possess animals and other people.
There must still be some rules about where he can go, and what he can see and do. Otherwise, he would probably travel back in time before it all hit the fan, possess people, and fix things.
What makes you think he CAN change things?
Last time he did something in the past, it only turned out that he was (and always has been) the cause for something that he knew all his life: A »dimwit« that can speak only one word. So if he goes back again, it might turn out that he is the cause for other things as well, but never changes anything.
Which would another Dr. Manhattan analogy, because he can’t change the past, too. I can’t remember if that line was in the movie, but in the comics, he said: »We’re all puppets. I’m just a puppet who can see the strings.«
For Bran, it seems to work a bit different: He can _influence_ the past, but (maybe) can’t _change_ it, because he lives in the »timeline« (to use SciFi speak) that he helped to create. He has already seen the outcome of his actions, even if he didn’t know that at the time when he saw them.
Yeah, just about every time travel story eventually arrives at a paradox and just stops making sense.
That line about seeing the strings is one of my all-time favorite pieces of comics dialogue!