Contrary to many ponies beliefs, Nightmare Moon was not a single entity. She was actually composed of both 'The Nightmare' and Princess Luna. And upon her banishment, they were split apart by the tremendous power of the Elements of Harmony.

Sending 'The Nightmare' to it's prison, and Luna to the misty and lonely town of Silent Hill to find her redemption.

Artwork by: aguantegrimtales (DeviantArt)