It was not long after the Alpha was put under his sleeping spell by Luna that war consumed all of Equestria. The evil unicorn king that ruled of the Crystal Empire, an isolated empire in the far north, surrounded by the world's tundra, by the name of King Sombra began to threaten Equestria. King Sombra had a heart darker than that of a black hole and ruled over the Crystal Empire with a topaz fist. Treating the crystal ponies that lived there as nothing more than slaves for his own sick means. The two Alicorns traveled to the Crystal Empire to stop the evil tyrant.
"Princess Celestia, and Princess Luna, what gives me the pleasure to have the both of you as an honored guest?" King Sombra asked the two alicorns, fully aware of the reason why the alicorn's were giving him a visit.
"Save your flattering Sombra, you know exactly why we are here!" Luna yelled at the shadow pony, her not in the best mood.
"Yes, I do, and what are you going to do to stop me." Sombra said, knowing fully that the two alicorns, or at least Celestia, didn't believe that killing was an option.
"We will defeat you!" Luna yelled at Sombra, take a step back, sarcastically grasping at his chest.
"And in what way do you plan on doing that?" Sombra asked the two alicorns, his muzzle warping into a devilish smirk.
" This is how." Luna said, as her horn glowed her blue aura as she fired her magic at the shadow pony.
Sombra blocked the beam, with his own black magic. "If war is what you want, then it is a war that you will get." Sombra said as his body warped into the shadows.
"Luna, what are you doing!" Celestia shouted, stopping her sister before she could chase after the cowardly King.
"I'm doing what you are incapable of doing!" Luna barked at her older sister, making the white alicorn take a step back. Luna's teal eyes seeming to burn with hate, as she opened her feathered wings and took off after Sombra. Heading straight toward the large castle in the center of the large city that made up the Crystal Empire, it almost unrecognizable from what it originally was. Dark crystal forming out of the supports of the castle.
Luna flew up to the top of the castle and land on the top, the cold air of the tundra swirling around her. A universal chill spread over her body as she trotted around the top of the castle. But she didn't care she was on a mission.
"Sombra where are you, come out and fight. Or are you just too much of a coward!" Luna had to yell over the wind.
"With pleasure." Sombra said as he warped out of the shadow, firing his black magic at the blue alicorn.
The blue alicorn was taken off guard and was unable to block the incoming blast. The black magic hit Luna directly in the chest, making her fly into one of the pillars of the castle.
Luna yelped out in pain, as she fired her own blue magic at the black pony. Sombra transformed his body into pure shadow, the beam passing harmlessly through him as he reverted back to his original form.
"That's cheating." Luna grunted, as she struggled to her hooves.
"No, that's biology." Sombra said to Luna, as he fired another black beam at the blue alicorn.
The black beam of magic was blocked, as Luna was surrounded in a small protective dome of golden magic, as her older sister landed on the top of the castle.
"Back away from my sister!" Celestia yelled at the shadow pony. Sombra taking a step back, as he realized that there was no way that he was going to win this battle.
"Are you ok Luna?" Celestia asked her sister, helping her to her hooves.
"Yeah I'm fine. Let finish this."
The two Alicorns lead in the air and combined their magic to defeat Sombra, by turning him into nothing more than shadow, and trapped him underneath the ice of the tundra that surrounded the empire. The spell that the two Alicorns used on Sombra had an unforeseen effect that it didn't just banish Sombra, but the entire empire along with him. As time went by Sombra along with his Empire would get forgotten from history. Only to be remembered by a select few ponies.
A few years later the draconequus, an animal with the head of a pony and the body of all sorts of different creatures. by the name of Discord, a pupil of Omega. Took advantage of the chaos caused by the two dragons fight, along with the Alicorns distraction of Sombra, and plunged Equestria into a kingdom of chaos.
The draconequus ruled over Equestria in a state of chaos until the two sisters discovered the six Elements of Harmony from the mystical Tree of Harmony that was located not far from their castle in the deep inside the Everfree Forest.
The two Alicorns used the Elements; Celestia wielding the Elements of Magic, Kindness, and Generosity, while her sister wielded the Elements of Loyalty, Honesty, and Laughter. The two Alicorns used the combined force of the six elements to defeat Discord turning him into stone. But before they turned Discord into stone he planted vines, that he hoped would drain the tree of its great power, and eventually free him from his stone prison. Knowing that he would return sooner or later, he was frozen in the stone. The expression on his face filled with laughter, rather than that of fear.
A few centuries passed and peace remained throughout Equestria, but it didn't last long. Ever since Luna had to put her best and really only friend under a sleeping spell she had begun to become a mare of darkness, both figuratively and literally. These feelings inside of her only got worse as she felt that her subjects rejected and shunned her night by sleeping through it.
These feelings that Luna kept inside of her began to corrupt her from the inside. Her bitterness toward her sister and subjects, the loneliness she had felt since the departure of her only friend, and the inability from her sister to be there for her when she need her most. Caused Luna to create a split personality to help her cope with her day to day problems.
This personality would later earn the name Nightmare Moon, and would use her flaws to turn her into nothing more but a weapon for its will.
One night in the two alicorn sisters' castle, on the night of the longest day Nightmare Moon took its chance.
"It is time for the ponies of this land to learn the true meaning of the night." The voice of Nightmare Moon said in Luna's head. "I agree it is now time for the our subjects to truly learn the beauty of our night." Luna said now embracing the darkness.
"Did you really expect me to sit idly by while they all basked in your precious light? There can only be one princess in Equestria. And that princess... will be me." Luna said confronting her sister in the throne room of their castle transforming completely into Nightmare Moon when she raised the moon in front the sun creating a solar eclipse, blanketing the landscape in darkness.
"Luna I will not fight, you must lower the moon. It is your duty." Celestia said to her sister.
"Luna? I am... Nightmare Moon and I have only one royal duty to destroy you." Luna said, Nightmare Moon now taking full control over her body. Nightmare Moon fired a light blue beam from her horn into the roof of the castle destroying it. Pieces from the destroyed ceiling came fall down scattering across the floor. Celestia opened her wings and flew through the hole the ceiling flying into the sky above the castle.
"And where do you think you're going." Nightmare Moon said to Celestia taking off into the sky after her sister. Nightmare Moon fired another beam of magic at her sister barely missing, instead hitting a column of the castle making it collapse. Celestia tha=en soared up into the pitch black sky the eclipse leaving a slight red tone across the sky as the Sun battled the Moon, in a battle that would change the night sky over Equestria for the next one thousand years. Nightmare Moon followed Celestia, her more powerful wings making her pass her sister in the sky.
Nightmare Moon then flipped back around and kicked her sister making her plummeted to the ground. Celestia used her wings to land safely on the green grass. Nightmare Moon fired her blue beam at Celestia. Celestia barely dodged it using her wings to glide across the ground before launching back into the sky, knowing that if she was going to survive this she had to fight back.
Celestia flew back up passed her sister and in an attack of self-defense Celestia fired her own gold beam at her sister. Nightmare Moon was pushed back by the beam before countering it with a small shield that surrounded her body. The sisters then fired their beams of magic at the same time at each other.
The two beams collided in a massive stream of light, the point of impact turning into a massive sphere of energy lighting up the pitch black sky. The beams battled until the more powerful beam filled with hatred and loneliness of Nightmare Moon's overpowering the lighter emotions filled one of Celestia. The beam from Nightmare Moon slammed into Celestia making her plummet from the sky, slamming through the door of the room that Elements of Harmony were kept in the castle.
When Celestia crashed into the room she slammed in the podium that held the Elements releasing the powerful Element of Magic from its dome. Celestia weaken from her fight with her sister noticed the Element falling toward the ground. As she noticed the Element Nightmare Moon crashed through the stain glass window.
Celestia with no other choice, in an act of self-defense, used the Elements against her sister. The six Elements of Harmony combined in a massive dome of rainbow colors surrounding Celestia in a protective circle and exploded outwards. Nightmare Moon slammed into the dome of magic and knocked her unconscious.
The force of the magic force Nightmare Moon out the window and banished her to the thing she controlled, the moon. Her image being engraved into the surface of the moon marking her imprisonment.
Celestia stared up at the pitch black moon, now with its right side imprinted with the image of her sister. Celestia mane now changed to that of a rainbow, from the usage of the Elements of Harmony, instead of its original pink. The white alicorn's pink eyes filled with tears until the floodgates broke and she cried at the loss of her sister.
After the defeat of Nightmare Moon, Celestia ruled over Equestria as a single ruler, raising both the sun and moon each and every night. Celestia left the castle of the two sisters, it being a reminder that she had to banish her own sister to the moon.
Much like how the Alpha did when he banished his brother to the outskirts of Equestria. Celestia founded the city of Canterlot and built a castle in its mountainous surroundings and she ruled over Equestria, as its merciful ruler for a thousand years, still retaining the title as Princess rather than Queen as to remember that the pony she still knew as Luna still remained trapped her own prison known as Nightmare Moon.
Not long after the defeat of Nightmare Moon a prophecy involving her return was created by a pony whose name has been lost to history. The prophecy stated "That on the longest day of the thousandth year, the stars will aid in her escape and she will bring about nighttime eternal." Little did anypony know that Nightmare Moon would return, and it would take six unlikely heroines to use the Elements of Harmony again. This time to free Luna from her real prison, Nightmare Moon.