[martin_fierro]

My completely speculative opinion is that things go so badly for The Living in the coming war that Bran has to time-travel back, become the Night King, and hobble The Deads’ effectiveness. < /guess >

[Hatteras]

Definitely thinking the Night King is a Stark. Bran's Uncle Brandon, perhaps? But first, I do want to see what becomes of the little stare-down between Bran and Jaime Lannister

[Nateman]

The problem with Bran doing anything with the Knight King is that this icy fellow knows when he is being watched. Remember that episode where he actually touched Bran?