[user104658]

Originally Posted by bitontheslide

Something that confused me .... Bran said the night king had sent many 3 eyed raven to try and kill Bran already. I don't even remember 1 having a good poke at him and isn't he now the 3 eyed raven .... i know he is meant to be an enigma ..... but unless ive somehow blacked it out, i can't make sense of that at all

U misheard. He said that the Night King has tried to wipe out the Three Eyed Raven many times before / has killed many previous iterations of the Three Eyed Raven (e.g. The previous one in the "Hooo'do'door! Episode) but has always been too late (with the abilities being passed on to the next host before he killed the previous one). He wants the Three Eyed Raven (Bran) GONE and probably is aware that this time, there's definitely no chance of him having trained up a replacement yet, so if Bran dies the Raven dies forever.

Regarding Little Sam... I think the sacrifice being missed is mostly at the time when the white walkers started moving south is mostly coincidence; it's definitely not their REASON for marching, and I can't see the Night King being all that bothered, although he may want to take the kid "on principle" and send one of his WW "generals" to fetch the kid, in which case yes I can see Sam killing another White Walker... Though I'd guess he'll save Gilly and Little Sam (and the others in the crypt) but will possibly die himself doing so.