The Mane Six and Spike thought that after freeing Rarity from the Nightmare Forces and saving the moon creatures that they'd seen the last of the evil. But unfortunately, it turns out that the Nightmare Force itself is immortal, and will always search for a new host. And it's next victim turns out to be the little sister of her last victim. With the voice of the Nightmare guiding her, Sweetie Belle gains her Singing Cutie Mark, but fear of being rejected by her friends gives the Force enough strength to turn the filly into Equestria's newest foe: Nightmare Knell.

(Button Mash is in this!!!!)