Thoraxis has become perfectly happy and content with his life in Ponyville, in the months following his "small" misadventure. His daughter, though, senses something missing, and sets him up on a blind date. With who just happens to be a wyvern.
Novel Tale, a changeling living in Canterlot as a writer, has his peaceful life shattered when changelings from another hive attack, revealing the existence of changelings to all of ponykind. And his last book had a changeling character in it...
History states that Princess Celestia banished Nightmare Moon away to the moon with the Elements of Harmony, that's true. But there was one other being present at the time who aided Celestia. A being who's magic can only be used by him and