Should have done one with the Pony of Shadows, seeing as how it's hinted that there is a possibility that the PoS may have had something to do with the creation of Nightmare Moon(like a Fragment of the PoS was left behind after he was banished to Limbo, and the Fragment had found it's way to Luna, where it tried to convince Luna to give in to her Negative Emotions, and the Fragment finally managed to Corrupt Luna enough to Bond with her, turning her into NMM).