The narration continues: their subjects, the ponies, played in the day but "shunned" the night and slept through it, which made the younger unicorn grow bitter, eventually refusing to lower the moon to make way for the dawn. Her bitterness transformed her into a "Wicked mare of darkness", Nightmare Moon. The elder sister reluctantly harnessed the power of the Elements of Harmony and banished her "in" the moon for 1,000 years, taking responsibility for both sun and moon, maintaining harmony in Equestria. The name incorporates several plays on words. She is, of course, a female pony, or "mare," and her black coat contrasts with Princess Celestia's white coat like night and day. But a "nightmare" is also a frightening dream. In folklore, a mare is an evil spirit who comes and sits on people's chests as they sleep, producing a terrifying sensation of suffocation. The original term is not historically related to the word meaning "female horse," but it has influenced the folk tradition, so that in some places the evil mare is said to turn the sleeper into a horse and ride the victim until exhausted.
In The LBT-MLP Crossover Movie, Her Dark Heart Jewel Was Found By Veloci. And She Was Reborn Into The World. She Thought That With A Powerful New Black Jewel Put On Her Helmet, She Could Be Unstoppable. But, She Was Wrong And Michael Beat Her With His Dinosaur Emerald Power And The Elements Of Harmony Together.