First, lets look at what we've got to play with. Assuming on the large side, if each book is the size of Storm (Book 3) or Dance (Book 5), and you assume a chapter count for Arya the likes of what she had in Clash, thats roughly 20-25 chapters worth of progress. Thats a decent amount, but also, assuming there won't be a time jump, it also won't take us 10 years into the future either. I'm guessing we won't see a grown-woman Arya by the end of the books.
Second, we need to look at what the main, overarching plots that affect the world, and if / how she might get involved in them.
You have a few plot threads that are hanging out there that aren't primary but could involve her, such as the fate of Rickon and/or Sansa. You also have the thought of whether she will run into Nymeria again. Those being mentioned, the main things would be:
- Her list
- The invasion of Aegon / return of Dany
- The war of Ice in the North against the Others
Her list is interesting because, I'm starting to realize, that those on her list almost tend to be brought *to her* (which raises interesting questions of its own) but also is a tangible goal for her to move towards. Gather information, travel, murder, rinse, repeat. This could serve as a plausible reason for her to travel almost anywhere, so long as she finds out someone she wants dead is there.
The invasion of Aegon / return of Daenerys proves an interesting one. It could be that she doesn't bother because they're doing her work for her, sort of, but also it occurs to me that, should (or maybe more like when) she leaves the Faceless Men, she could essentially put herself out as a blade for hire and work FOR one of them, and use that as a way to legitimize killing the listies that are left. This is all assuming she manages to make a clean break from the Faceless Men. I don't even know what being pursued by their guild would look like. Good luck getting to sleep if you're in that spot!
Finally, the War of Ice. We all want Arya to meet up with Jon again. Their relationship is one of the strongest examples of tenderness and happiness that sticks in our heads, and the memories of Jon mussing her hair and calling her "little sister" is one of the most dear things to her. Having the characters meet one another after they've both undergone such large transformations, and having experienced so much would be a heartbreaking, tear-jerker of a moment. It also may be the thing that breaks the massive walls Arya has built up around herself.
Given the visions of Arya in the ice that I believe Bran had in book 1, I imagine she will end up in the north / at The Wall for one reason or another. What I worry about is if she winds up playing a part in killing a key figure on the side of good, either intentionally or unknowingly. Perhaps it would end up being one of those "short term, good idea; long term, bad idea" situations.
I feel very confident saying she will be the death of some key players, though who is anyone's guess. She will most likely be the avatar of death to some degree, and it's feeling like The Winds of Winter will be another Storm of Swords; another Empire Strikes Back "dark period" for the story.
I think at the end of everything, Arya will end up either tragically broken, or hugely redeemed or reborn. I think her story is a huge journey into the depths of her soul and looking at what can happen to even a sweet, rambunctious girl when rage, fear, lonliness and vengeance rule your path. I hope, for her sake, she finds peace and family again. I hope she finds safety again. I hope she finds real joy and a new purpose.
