The 500th Nightmare Night was supposed to be a special celebration. But things go terribly wrong when a demon king rises from the shadows and kidnaps Apple Bloom to take as his bride. Bad luck. That leaves the rest of the CMC to try and save their friend from his clutches before he completes his dark ritual.

The pic is my thought process on how this came about.

When Ricky falls asleep in class, he dreams up a team of Pinkie Pie and Sweetie Belle, with who he must defeat an evil being that seeks control of this dream world.

It's a beautiful Winter day in Ponyville, and Celestia tasks her faithful student with gathering some rare winter herbs. During the quest, Twilight ends up making a wish on a shooting star for the next day to be more interesting. That night, she is visited in her dreams by a shape-shifting creature, and the next day meets a stallion in the Everfree Forest who has lost his memory. As Twilight grows closer to this pony, a dark past unfolds and threatens Ponyville, but is it somehow related to him?