I think the Night King is known from lore, and he was named as such. Just like we all know who "the devil" is, now let's make a huge stretch of imagination and let's forget that most traits of Satan are basically pop culture, if "Satan" starts to show up in the world, we'd refer to him as the devil, I take that it's the same with the Night King. I prefer him called the Night King however, makes it more general and menacing, Night's King alone seems a bit still for a proper name.
Anyway, biggest waste of Ian McShane ever, did he want a cameo so they found a part for him, or did the writers really want him but he was busy so he was like "Ok, guys, but I need a short part"? good to see the Hound back however!
And I refuse to believe Arya's gonna kick the bucket that way.
Also, Jaimie punching one of Walder's sons was awesome. And boys does the Blackfish have balls.
Three episodes left, what do you all think it's gonna be the last scene of the season? Tower of Joy flashback? someone going How I Met your Mother on Jon? Dany finally deciding to bring her butt to Westeros? An apocalyptic scene, like, say, Tommen dead for whatever reason and the future of King's Landing left in balance? or even the Night's King arriving at the Wall, even though I assume it's a bit too early for that?