Princess Luna is a secondary character in "My Little Pony: Friendship Is Magic." She is Celestia's sister, and controls the night and moon. At one point she was so overwhelmed with jealousy about how day was appreciated more than night and attacked her sister, threatening to cause everlasting night. She was defeated and imprisoned in the moon as a marking similar to the "man in the moon," but escaped 1000 years later. Shortly after her return and new threats of eternal night, she was defeated by the Elements of Harmony as wielded by the six primary characters of the series and purged of the evil that had overtaken her. Since then, she has returned to her position as co-ruler of Equestria. She has appeared in minor roles several times during the series, and has also had an episode about her trouble adjusting to the informality of modern society and her reputation as an evil usurper of the throne. Although she has had relatively few appearances, she is in fan art quite frequently.