Pinkie Pie was unable to turn things around and the Yaks refuse to become friends. Instead of friendship, Twilight has to put a stop to a new threat to her young kingdom before her friends and others are harmed.
But even if they are defeated, Twilight and the other princesses must consider whether it's possible for Equestria to coexist with such a dangerously xenophobic society.

(Fan fiction of "Party Pooped" [Season 5, Episode 11] which does not abide by how the episode ends. Ribbon Wishes is from "Cutie Mark Wishes")