MLP:FIM: Crystal Curse

In a time long ago, there was kingdom known as Equestria: A land where every pony knew each other and had no problems with that, war was almost unknown to the point that peace had reigned there for centuries (well with the exception of a couple of threats (I wont name any names)) and all the creatures in the land were polite and helpful at all times (and not just to earn the satisfaction and gratitude of others). The kingdom was ruled by two monarchs.... princesses to be exact: Celestia and Luna and they were (in all honesty) decent rulers of the realm. Each princess had duties to perform: Celestia raised the sun across the sky during the day while Luna raised the moon when the day was good and over.

However, Luna (being the concerned co-ruler of the realm) looked upon her duty with great sorrow as during the day, every pony was awake and going about their normal routines with great content and happiness while during the night they finished what they did and slept for the rest of the night. And so with defiance greater than anything any pony has every seen she refused to raise the moon no longer, reasoning that there was no excuse whatsoever not to stay up during what should be a joyous moment that every pony can enjoy.

Princess Celestia was concerned for the welfare for all residents of her kingdom and had her sister banished from the realm, imprisoning her on the moon in exile and made sure she would not escape until Luna had calmed herself and returned to her benevolent ways. However, all this did was make Luna resent her sister and all the inhabitants in Equestria thus warping her mind and creating Nightmare Moon: a vile, unremorseful sorceress who knew only resentment. Now as a former shadow of herself she plotted in silence, seething with rage and abiding her time until the opportunity to invade fair Equestria had revealed itself to her.

At last, when the timing was just right she appeared before the bewildered audience of ponyville (who had eagerly awaited Princess Celestia to arrive for the summer sun celebration and raise the sun as she had always done many a year before) and announcing everlasting darkness upon the land. Attempts made by the royal guard and the villagers were futile and it was not until six ponies, each from different backgrounds, had banded together to find the fabled elements of harmony: six legendary trinkets that had the power to defeat even the most chaotic of foes. Fearing her defeat would come as quick as her arrival had, Nightmare Moon planned to hinder the six ponies at every twist and turn, trying to throw them from the path that had been set for them.

However, no matter how many times she tried to deter them only made them realize just how lucky they were to have each other and, as they reached the ancient castle of the royal pony sisters they managed to reawaken the sleeping powers of the elements. and defeat the mad sorceress utterly, returning Luna to her natural state. Forgiven by her sister and celebrated once more as the benevolent co-ruler of Equestria, she returned to her duties as the bringer and ruler of night. The six ponies who helped bring the reign of the mad sorceress to an abrupt and 'permanent' end went down in history as the Mane Six and there came upon the land peace and harmony (and of course more of Pinkie Pie's parties to follow). The tranquility was said to have lasted for a year until, as quickly as her defeat had come, the Mare of the Moon returned