Dream On

Luna has been having nightmares more often, and so has the rest of the Mane Six and their other friends. Though the Tantabus is dismissed immediately, and the Nightmare Forces that turned Luna into Nightmare Moon are not responsible since they were cured of the darkness Pitch reaped on them thanks to the Mane Six, they tie this to a powerful spirit similar to the Tantabus but far more frightening known as Nocnista, which is a nightmare spirit that Luna defeated long ago, and yet disappeared before she could seal it away as it adapted to her powers. After looking for clues, it's revealed that it was previously defeated already by another one of Starswirl's past students, Zodiac Cloud, who lives in a hippodrome in Hollow Shades turned into his legendary Temple where he helped educate to prevent Pitch's oath of haunting a future generation come true by having a hoof in his remembrance, as he had cured the Taraxippus that haunted him by discovering it was in love with him because it was born from a pony that died from bullies accidentally after a long time of loneliness, and married her and had kids before they were killed by Nocnista herself, until he sealed her into a prison in his educational realm, the Uncanny Valley, which is a realm that combines both the real world with the subconscious to allow easier fighting against internal and external forces combined, and though the setting has the same physiology as a dream like nonsense, surrealism, and so on, it provides a good place of training such as lucid dreaming, and fighting against mind domination or illusions, or even counter-attack. As the result of Bishop Dipper's terrorism with the Taraxippuses as the new Pony of Shadows, he has ended up freeing Nocnista as it seeks to be the new Pitch Black and free the Taraxippuses to help fight to make fear both mental and outer to gain more strength. When it gets stronger every passing night, the Lodgers, who end up experiencing Nocnista's influence upon arrival, must do what they can to save their Equestrian friends from this haunting threat.