The Rainboom gives Discord a chance to escape his statue early. Now he's stuck raising six amnesiac fillies that will probably be his enemies one day. Lovely.
Discord is doing a great job being a good friend, but he's been rather passive in the endeavor--he never makes friends of his own. Celestia decides to remedy the situation and complete Discord's redemption by having HIM redeem somepony special.
Discord, the lord of chaos. Ageless being with unlimited powers that nopony can hope to match. What if the blast he took from Sombra was very real and very harmful.
After Discord failed to break up Twilight's friendships, he decides to trade places with a future Discord where the Elements would no longer exist. A future where, unknown to him, Discord has been reformed...