I don't get the whole "click-bait" article (not specifically that one above, but I've seen many others) that say Bran is the Night King.
Don't we already know that the Night King is some old Stark that was a disgraced Lord Commander?
While I guessed in the past that Bran would Warg a dragon, I guess the answer now is that he is going to Warg an undead dragon out from under the Night King. He probably dies in the process or something, but I can't really see it going any other way. Otherwise, what the hell is the point of Bran's "powers" besides him "legitimizing" John and substantiating the Targaryen incest rule?