A year after Jerome Valeska is killed by Theo Galavan, his cult attempts to revive him. As they do, a certain Starlight Glimmer accidently sends out a summoning spell that happens to hit Jerome's dead body. Apparently, it also had a life giving spell in it as well, because he returns to life shortly afterwards. Almost immediately, everypony realizes how dangerous he is when two ponies are found dead. When they find out he wants to get back to Earth to kill Bruce Wayne, they know it's up to them to stop him before it's too late.

Ten years after Mario's very first adventure in Super Mario Brothers Peach is kidnapped by Bowser. Again. Bowser plans to marry Peach, whether she wants to or not. Mario, after a failed attempt at saving her, meets Cappy, a magical hat, in the village of Bonneton. After going to several kingdoms, Mario and Cappy almost reach Bowser's kingdom, only for Bowser to outwit them by turning loose a magical dragon to attack them. A dragon which uses its fire at exactly the same time as an alicorn named Twilight Sparkle uses a teleporting spell. The Odyssey ends up getting sucked through a wormhole, and crash lands in Equestria, where Mario and Cappy try to make friends with the six main ponies and the other ponies. At the same time, they know the clock is ticking, and it's only a matter of time before Bower and Peach weds, and every kingdom falls under Bowser's rule. It's up to Mario, Cappy, and the six ponies to stop him, or the world they know will be demolished.

Summary: When Rainbow Dash performs her first Sonic Rainboom as a filly, she causes a young filly Twilight Sparkle to shoot several beams into the sky. Ten years later, those beams appear in various different worlds and teleport characters from Super Smash Bros., DC Comics, Marvel, Star Wars, Percy Jackson, and a regular human into Equestria. Not long afterwards, an old foe of Luke Skywalker’s terrorizes the land. And when a new foe, even deadlier than any enemy ever before seen, is born, he wishes to destroy the Elements of Harmony. If he succeeds, Equestria, followed by the universe, will crumble. Not only that, but the human has connections with him. Connections which make things worse. Together, the group must stop this foe. The stakes have never been higher, and if they fail, the universe will fall.