But even if the prophecy has already happened what is wrong with people wanting him to die by Sansa's hands? IMO it would be fitting. Since you already said that Sansa is his Achilles heel wouldn't it be fitting for Sansa to defeat him? Sansa defeating him in his own game would be sweet justice all the wrong he has done. Sansa needs to be his karma, because he molesting her at the moment. I want Sansa to break free from her cage and once for all fly away. That won't happen until he is dead.
My problem is mainly with people pointing to the prophecy as “proof” that she’s going to kill him, when it’s not. It’s just gotten parroted around so much as a valid theory that it’s practically indisputable fanon at this point, like R+L=J (except I think R+L=J is actually going to be confirmed).
The reason so many people root for Sansa to kill Petyr is because they hate him and they want him to be served “karmic justice”. It would also be, IMO, bad storytelling, particularly in the context of ASOIAF as a whole, and it does a disservice to one of the most complex and intriguing relationships in the series. Sansa is the reader’s only window into Petyr’s machinations (she didn’t become my favorite POV until ASOS for that very reason) because he’s chosen to not only confide in her, but to school her in the game. His interest in her is not merely that he looks at her and sees Cat; he looks at her and sees himself, as a youth whose own romantic dreams were crushed (hence, his warning of “life is not a song.”)
Sansa not only learns quickly from him, she begins developing a split personality of her own to mirror his. Alayne has made her stronger, braver, and savvier. I’ve said this before, but I think of the Alayne persona as basically Sansa’s cocoon, from which she’ll emerge as a true player. There’s also the fact that he clearly intends to lift up Sansa for Winterfell and rally the North and Vale around her. And this scheme, when he presents it to her, feels more like a courtship offering than anything else, basically a moment of “what other guy is going to do all this for you?”
Sansa, by the way, basically has Stockholm syndrome at this point in regards to Petyr. She makes justifications for his actions, she thinks of the two of them as a team (“Father and I have larger concerns”) and in the final Alayne chapter of AFFC, which reads like one long, hormonal prelude to Sansa’s imminent sexual awakening, her reaction to Petyr’s kiss is to blush, not to rebuff him.
I’m definitely not saying this is a healthy relationship, but it’s an interesting one for sure. I’ve practically written a thesis on the damn thing already.
But here’s the main thing: where is Sansa going to go if she “breaks free” before she’s prepared to face the world again? What is she going to do? Have someone else take care of her, thereby making her entire character development up to this point null and void? Then what the hell was the point of every Sansa chapter since ASOS?
No, I want to see Sansa as a formidable Queen. Remember when she said to Cersei “I’ll be a queen just like you someday?” Actually, she’ll be a BETTER one, because she has the best chessmaster in Westeros teaching her. And he’s the only one offering her two kingdoms, with a hunky knight at no extra cost.
Now, plenty of people want both this AND her killing him in a Vader/Palpatine moment, but unless she learns how to force-choke people that’s just going to be lame, so no thanks. I want him alive and trollin’ forever. Preferably as her Hand.