Reddit user turm0il26 is responsible for the brilliant theory that Bran is actually the Night King, and as season seven has progressed, it's only becoming more plausible. The theory suggests that Bran is flying through time desperately trying to stop the White Walkers before they have a chance to wreak havoc in the present. Ignoring the Three-Eyed Raven's warning that "the ink is dry" on history, Bran will eventually warg into the First Man who is kidnapped by the Children of the Forest and turned into the Night King. Unfortunately for Bran, when the dragonglass is plunged into the man's heart, the youngest living Stark will become trapped in his body and ultimately become the monster he had hoped to defeat.