Three years ago . . .
Flurry Heart united Equestria and the Crystal Empire into a single nation after the war against Grogar to protect friendship in all of its forms. Little does anybody know that only Grogar's body was destroyed. His soul has secluded itself in a faraway cave and mutated to get stronger.
Can Flurry Heart stop this threat when Grogar's soul comes out of hiding, or is the world doomed to lose all knowledge of friendship?