9 Game Of Thrones Warriors Who Could Defeat The Night's King

Sure she's just a kid - but she's a kid with some pretty serious skills, which will undoubtedly only improve under the guidance of the Faceless Men, blind or otherwise. The question is: would Arya even care enough to try to take down the Night's King?

Since her father's head was lobbed off just a few feet away from her, Arya has obviously undergone quite a change. Always interested in swordplay, being forced to survive the wilds of Westeros heightened her skills considerably and she is now a pretty capable warrior - not to mention a ruthless, stone cold killer. 

Arya's never shown much concern for the problems of Westeros though, and seems to be on her way to abandoning all that's left of her old self to become... well, "someone else". Still, being blinded (spoiler: it won't last) at the end of the season 5 finale might give her a different perspective on things and there's no doubt she will play a more important role in the final books/seasons than a Braavosi-based assassin. 

Replace Needle with a little Valyrian steel sword, point her in the right direction, and let her cat-like stealth and killer instincts do the rest.