Once a pond a time, in an era after the horrific God of Madness was imprisoned in stone, there were two mares who rule over the land of Equestria. A pair of sisters. Tia, the one who was beautiful as the sun, and Lu the one who was as quiet as the night. They were Alicorns, having the magical abilities of the three pony-races, Earth Pony, Pegasus, Unicorn, combined and their power were beyond any pony could ever reach. All though, that's not the only reason why they and they alone rule Equestria.
They were chosen by the Elements of Harmony to weld their holy power. Tia was chosen by the Elements of Honesty, Mercy, and Sorcery. While Lu was selected by the Elements of Bravery, Generosity, and Hope. With the Elements of Harmony, the sisters ruled and protected the land from any and all evil that came their way.
But one day, that all changed...
The ponies of the land favored Tia over Lu, believing that she was chosen by the sturdiest haft of the Elements. Therefore, she was the most powerful of the two sisters and Lu wasn't needed in the slightest. This favoritism was driven to the point where Tia was crowned as the official queen of the land. Jealously took over Lu, causing her to leave her Elements behind, along with her sister.
Tia tried to find her beloved sister, sending out search team after search team to bring her little sister back. None of them showed any result. Many years passed, Tia grew sick from her grief and pondered if she should even continue searching for her sister or just give up. Then, out of the blue, Lu came back. But she was far from the beloved sister Tia once knew.
She trotted through the castle, whispering to the darkness that followed shortly behind her. Once she made it to the throne room, where Tia could see her, her face said it all. She was cold, angry, and had an intense thirst for blood... Lu attacked her sister, using a spell that no pony had ever seen before. Hitting the young queen's left wing and turning it into pure glass. Lu pulled out a long sword made from Twilight as a red cosmic cloud swirled around the sword. She and the darkness lunged at Tia, both aiming for the newly formed glass wing. Tia barely dodged, only getting a scratch on her left back leg.
This was the begging of a battle that lasted for three days and four nights, ending many lives and reshaping the land they once protected. On the final night, Tia retrieved the Elements of Harmony. Years prior, the Elements of Harmony were used to transform Discord, the God of Madness, into stone until the end of time. Tia tried her hardest to avoid using them on her sister. But at this point, she had no choice.
With tearful eyes, she used the Elements of Harmony, a massive bean of colorful light swirled around her before aiming towards Lu. However, the beam didn't hit Lu, not even close. Against all the odds, Lu caught the beam with her own magic. Her eye, ears, nose, and mouth started to bleed as her spell mixed into the beam.
In utter awe at the sight, Tia barely noticed that the Elements of Harmony was slowly dying. Since the battle started, the harmony between the sister was fading, so did their connection to the Elements of Harmony... The Elements of Harmony dropped onto the ground, fully transformed into their hollow state. Tia crumbled, getting onto the field and begging for them to come back to life. With no such luck. Tia looked up at the sky where her once kind and loving sister was, gaining control over the beam she shot at her. She excepted her faith, preparing herself for the beam's impact. But instead of aiming the beam at her defeated sister, Lu had another idea.
Lu shot it into the sky, the beam hitting the moon with great force. Lu used all her power to carve a black outline of a head and neck of a unicorn. Once she finished the unbelievable feet, she fell to the ground not too far from Tia, weaken and wounded. Lu slowly got up, trotted slowly to her stunned sister who was unable to move. She stopped right in front of her, lowered her bleeding head inches from Tia's face and pointed toward the carving on the moon.
"Listen what I say and listen well, Queen Tia." Lu said coldly. "When the eyes of The Mare of the Moon open, I, The Nightmare Knight will return and finished what I started..."
"What is that...?" Tai stuttered sorrow and fear painted in her eyes.
"To chop your little head off and feed it to the wendigos."
Then, without another word, she turned around and walked away. Never to be seen again...
A thousand years and a lot have changed since then. Equestria grew in mass and number, harmony was made with several other races. Even a new kingdom was formed, ruled over by a young queen with her fateful husband on her side. Most ponies excepted the existence of the Mare of the Moon in their lives.
But the queen was still scared from that battle all those years ago and lived in fear of the day that her sister would return. And she was far from being the one. Most of the ponies in Equestria feared the Nightmare Knight, unable to imagine the horrible fate their queen would face if she'd returned. A brutal death that would bring the land into darkness.
For the Elements of Harmony themselves remained lifeless since that day. Any and all attempts of bringing them back end in failure. That was until one day, the Elements of Harmony was suddenly brought back to life by six little fillies, who got their cutie marks on the exacted same day at the exacted same time...
-End of Prologue-
