Shortly after the first Hearts Warming Eve, Celestia and Luna takes control of the sun and moon. Celestia and Luna Start to help Equestria grow when a draconequus named Discord see's the 2 sisters and wants to test the limits of the alicorn rulers. First it starts as harmless pranks, and mild flirting but after he figuring out that he is slightly more powerful, Discord takes full advantage of the situation and decides he is going to become the new ruler of Equestria. Celestia and Luna find a way to stop discord and take full responsible for the protection of Equestria. They soon discover that their are Crystal ponies who are enslaved in the far north by a ruthless King. The 2 sister rally the citizens of Equestria together to help free the Crystal ponies, only to loss the whole city to a curse. This loss was too much for Celestia and she losses sight of what is important. Luna also losses her way, and starts to see Celestia as becoming weak. Luna embraces the inner darkness to become the one and only ruler of Equestria.