Is Bran Stark the Night King?
What if Bran’s desire to change the past ultimately made him a prisoner of it? According to this theory, Bran’s attempt at correcting history made him cause an apocalyptic future.
Time and again, Bran failed to stop the coming of the White Walkers. Despite his best efforts, he accidentally made Aerys go mad and he warged into the legendary Brandon the Builder to erect The Wall.
When his efforts offered no hope, he hurtled himself further into the past and the moment the Children of the Forest plunged a dragonglass blade into the heart of the First Man. At the scene of the crime, Bran warged into this man to curb the creation of the White Walkers altogether. While he tried to negotiate with the Children of the Forest, he ultimately failed, was strapped to a tree, and turned into the Night King himself. Through all of this, Bran “drowned” in the weirwood net and lost his consciousness within it.
After this moment was revealed by the Children of the Forest in season six, Bran was shown sitting in the exact position as the First Man tied to the tree. As he did when the Night King interrupted his visions beyond The Wall, Bran reacted to the stabbing as if he felt it himself.
According to this theory, Bran Stark is the Night King, and he built The Wall as a preventative measure against himself. Therefore, “winter is coming” is synonymous with the arrival of Bran in the form of the Night King. However crackpot it may seem, this theory aligns with the tales of Old Nan:
"Thousands and thousands of years ago, Brandon the Builder had raised Winterfell, and some said the Wall. Sometimes Nan would talk to him as if he were her Brandon, the baby she had nursed all those years ago, and sometimes she confused him with his uncle Brandon, who was killed by the Mad King before Bran was even born. She had lived so long, Mother had told him once, that all the Brandon Starks had become one person in her head."
The show has made it clear that Bran Stark and the Night King share similar powers. As Bran can do with beasts and birds, the leader of the White Walkers effectively wargs into the wights, both people and animals, while simultaneously moving in and out of Bran's visions. The larger theory may belong more in the “hypothesis” category, but it’s tethered to the incontrovertible connection between Bran Stark and the Night King. From subtle symbolism in the show to clues in the books, there’s more than enough evidence to suggest that something is rotten in the state of Bran Stark.
This we know: George R. R. Martin has promised a “bittersweet” ending to his beloved fantasy tale, while David Benioff and D.B. Weiss have alluded to a final properly mind-blowing moment in season 8. There are no better candidates for that sort of conclusion than Bran Stark and the Night King.