Casso King of Seals replied to Hmadkour's topic in The Winds of WinterYou're focusing way too heavily on the "mission" part of George's quote. What strikes me as much more relevant is the broader idea of loss of humanity and altered personalities through resurrection. We've seen that a ton. Aeron and Patchface, for non-wight, non-Rh'llor examples. But to humor you on the mission thing, Gregor's sole purpose in undeath seems to be to serve his queen. (Or perhaps Qyburn. Uh oh!) And assuming Coldhands is Benjen, he's clinging to his ultimate mission of defending the realm against the horrors of the north. How does that not work exactly?
All we need here is something to interrupt the execution of Jaime. This is George, absolutely any sequence of events could happen from left field. If we're pressed for options, may I suggest Nymeria and her giant wolf pack, or maybe the Blackfish stumbles into Hollow Hill? The Freys finally launch an offensive? Are any of the Bloody Mummers left? Zollo's still alive, right, the one who chopped off Jaime's hand? There you go, poetic justice. Anyway, bang, Jaime and Brienne escape - forever changed! - and go on to complete whatever their story arcs are going to be. I do hope Catelyn and the BwB become more prominent threats, though, I love 'em. So much potential.