Once upon a time, in a faraway land called Equestria, there lived a beautiful princess named Celestia. All of her subjects loved her for her beauty, and for the stability she brought the land. However, Celestia was vain. She had a magical mirror that she would stare into for hours on end. In the mirror lived a nightmare, an evil spirit capable of infecting the unwary, and it was bound to the princess. Every day, she would ask the mirror, "Mirror mirror, on the wall, who is the fairest of them all?" Then, a horrible face would appear in the mirror, the face of everything the ponies hated, the face of Nightmare Moon. The awful apparition always would reply, "You, sister. Of course you are the fairest. After all, you are my sister." Nightmare Moon would then sink back into the magical abyss and plan her eventual escape.
The story of Celestia's decline is an odd one. For a thousand years, she ruled well, alongside her sister, Luna. Celestia raised the sun, and Luna raised the moon. One day, the sisters cast a powerful spell to create more stars. That day, something went wrong. The spell... fizzled. The princesses thought that it had simply been a failed attempt, that nothing had happened. They were wrong. That day, something evil was created, a spirit that could not be destroyed. The next day, Celestia woke up to find Luna scrunched up on the floor, her face a mask of pure torment. Celestia was horrified. She wanted to save her sister. "Luna, whatever is the matter?" she asked. Rising from the ground, Luna seemed taller and darker than before. Her mane and tail were no longer light blue, but looked like the night sky, full of a thousand stars. In a voice as cold as ice, the unrecognizable pony cried, "Luna is gone. I am Nightmare Moon, and the night... Will last... FOREVER!" The awful shell of Luna flew out the window on powerful wings wearing armor of steel.
Celestia grieved for her lost sister, the last member of her family, but she mostly grieved for Equestria. A single tear ran down her cheek as she wondered if the land would ever be at peace again. That night, she resolved to defeat Nightmare Moon, and return harmony to Equestria. She gathered the Elements of Harmony and set out. She eventually vanquished the dark mare, using the Elements to cast Nightmare Moon out of Luna's body. Most ponies believed that Nightmare, still in Luna's body, was sent to the moon, but the truth is that the spirit left Luna, and was imprisoned in Celestia's mirror, and Luna herself was thrown across Equestria by the force of the spell used.
For a few years after Nightmare Moon's defeat, Celestia was a good queen. As everypony now knows, however, absolute power corrupts absolutely. It wasn't long before enemies of Celestia began to disappear, along with anypony who could rival her beauty. Nopony who knew of Celestia's evil dared oppose her, and most ponies just had no knowledge of it. Celestia made sure to shower her subjects with spells to keep their loyalty, however, the purest ponies were immune to these spells, and so were the most powerful or corrupt. Anypony with outstanding beauty would generally try to hide under baggy clothing and ugly makeup. One night, Celestia was looking into her mirror, and admiring her reflection. "Mirror, mirror on the wall, who is the fairest of them all?" At once, Nightmare Moon's reflection replaced Celestia's. "You are, sister. But there is another pony destined to surpass you." Celestia gasped. "Who is it?!" Nightmare recognized an opportunity here. "I won't tell you unless you free me from this mirror. "You and I both know that will never happen. Now, tell me or I break this mirror and free you from this dimension!" Celestia threatened. "Oh, wow, look who is in a bad mood," Nightmare mumbled sarcastically. "The pony is Rarity." "Show her to me," Celestia demanded. Nightmare Moon looked startled. "Fine, I will display her, but I'm not talking to you anymore today." On the surface of the mirror appeared an image of a beautiful white pony with a perfect purple mane appeared. "I will destroy you," Celestia murmured, "but first I must find you."
