It all started when I asked myself a question, What if the Mane 6 & the CMC meet Harry Potter?
Discord is aware of alternate realities but he usually ignores them for his love of Fluttershy and Equestria in that order. When he gets a call for help from one of the other spirits that governs those realities, Discord does it in the most chaotic way possible, he sends The Elements of Harmony and the Cutie Mark Crusaders. In order for the survival of everything, Harmony must spread.