Note: The following events occur between seasons 2 and 3 of the MLPFIM series.

Twilight Sparkle and her close group of friends are called to Canterlot by Princess Celestia and Princess Luna. An old foe from Celestia's past has returned from exile and plans to attack the castle with a horde of monsters at his beckon call. This diabolical villain intends to control all of Equestria and will stop at nothing to get what he wants. And his name is...