Celestia and Luna have been at war for a thousand years. Billions of lives have been sacrificed in the name of 'The True Ruler of Equestria'.

It started long ago, when Nightmare Moon first took over The Princess of the Night. Celestia fought bravely to defend the balance of day and night, but was no match. Her fallback plan was to use the power of the Elements of harmony and dispel the evil that had corrupted her loved sister... that evil was too pure. The elements of harmony failed. Left with no other choice, Celestia abandoned the fight and retreated.

Several months rolled past as Celestia hid from her sister's forces. Approached by a mysterious figure, Celestia was promised the necessary power to help Luna. In her emotionally destraught state, Celestia was blind to the obvious and begged for the ability to have her sister back. The figure opened Celestia to the power and pointed her in the right direction to rise up and fight her way to Luna... but it wasn't to help her.