The rearrival of Nightmare Moon, the release of Discord, the attack of Queen Chrysalis and the changelings, the return of King Sombra and the Crystal Empire, and the princess coronation of Twilight Sparkle; all those were just signs of the arrival of the biggest and greatest threat known to all. The threat that not only Equestria has feared, but the whole world.
The gates will be opened, the seal will be undone and the enemy will be released, to bring ruin, fire and darkness upon the world. Heaven and hell will collide, and the mortal world will be their battlefield. The demons will come from the world of burning sulfur, and bring all of existence to justice and death forever and the world apocalypse. The secrets and mythologies hidden from the world for 10,000 years shall be revealed.
Can Twilight Sparkle, the rest of the main six, Spike, and the princesses of Equestria bring down the upcoming threat and handle such doomsday, or will it be too late?
The events of the story takes place after Magical Mystery Cure and is directed to the twist consequences of one of the events in It's About Time. (Both episodes are written by M.A. Larson)