[Slice of Life]
Author: Caligari87
Description: Twilight Sparkle has spent years as Discord's protégé, studying the Magic of Chaos. But when rumors of a strange phenomenon dubbed "Friendship" show up in a small outlying town, the Emperor sends his star student to find out what's going on. Twilight goes with the best intentions and quickly discovers there is more than meets the eye going on in Ponyville...
The Assembled Letters of Twilight Sparkle, Protégé of Emperor Discord
Twilight Sparkle, Bringer of Chaos (Update Sequel Complete!)
Additional Tags: Discord's faithful student discovers friendship