The Legions of the Old Equestria were the most feared warriors in the world. One Legion in particular was seen as the Demons of Tartarus, the bloodthirsty fighters that did not know mercy. The XVI Legion of Equestria was forever known as "The Dark Legion." Their name forever carved into history.

Many years later, Princess Twilight Sparkle discovered documents and journals from soldiers of the XVI Legion, along with a few others. Now she begins a daring research project in order to find out more about them. This, however, will lead to some dark and mysterious happenings within the walls of Canterlot and the Everfree Forest.

Warning: This story contains graphic violence, language, blood, guts, and horrifying images. Viewer discretion is advised.