Queen Solaris and Queen Lunara were Celestia and Luna's mothers and they sealed away a dangerous and ancient evil who took the form of a female Draconequus named Discordia. What they didn't know was that one day Discordia would return. Twilight was exploring the Castle of the Two Sisters when she found a Book with a seal on it that looked like Discord but there was a second Draconequus as well forming a yin Yang circle. Twilight was intrigued and broke the seal releasing a huge burst of chaos magic into the air. She backed away only for the magic to flow into her unlocking hidden memories and her true identity.