Emerald was just another human, just another pegasister. Now she's been turned into an OC pony called Twivine. Problem is, she has no idea who Twivine is.
Twilight changes Star Swirl's time spell to travel back to the past once more. She ends up in the Pre-Equestrian era and unwittingly saves two fillies in the process. Little did she know what teaching them magic can do for the fate of Equestria.