Some things are best left behind us...
1000 Years before 'Friendship is Magic'
Luna stared out at the night sky. At HER night sky. Even though it could be said by some to be a time where ponies simply slept, and didn’t pay attention to her majestic creation, she knew better. The stars were truly a wonder, and she could feel the loving glances ponies gave her sky.
All was fine in Equestria. Although the Crystal Empire was entombed in slumber, Discord was frozen in stone, thanks to the Elements of Harmony. He had caused enough chaos as it was, and it would certainly be for the worse if he was free.
She heard a walking sound behind her, and Luna looked over her shoulder to see her older sister Celestia walking up.’
"Hello, Tia. Tis a good night to be outside, don't you think?" Luna said.
Her sister shook her head. "Luna, we need to talk." She said in a tone that made Luna worry.
"What about, Tia?" Luna responded.
Celestia sighed. "Ponies actually enjoy your night, Luna."
Luna frowned. "I don't see how that would be a problem."
Celestia shook her head. "That's just the point. You DON'T understand. I work hard to raise the sun every morning, and lower it in the evening, all so MY ponies can live!" Celestia seemed to be getting more angry, and it frightened Luna. Badly.
"They just look at it and treat it as if it's just a regular event, while they stare at your night as if it's the seventh wonder of the world!"
Luna gasped. "But Tia! The ponies appreciate you for what you do!"
"Do they?" Celestia said in a maddened tone. Her form was staring to get more and more grey, for what reason Luna couldn't tell. "They frolic about, without a care in the world, under MY sun! And they thank me, oh they thank me. But do they ever behold it with the wonder they do your night? No!"
Celestia was turning a darker shade of grey every moment, frightening Luna.
"Sister, what has afflicted you?" She asked in serious alarm.
Celestia gave a maddened grin. "The truth has! From now on, I proclaim the reign of eternal day! No longer will ponies have to be in the dark; now they can finally be free! Under MY rule!"
"Celestia, stop this at once!" Luna cried.
"I am no longer Celestia!" Her sister shouted. "I am Solar Storm, and you WILL bow down to me!"
Luna quickly teleported away, running through the hallways. Looking out the window, she could see intense light gathering outside. Her night was gone, and ponies were being slowly blinded by the intense glare.
She burst through the doors of a hallway, passing stained-glass windows, and but her horn inside of a slot in a door. It opened slowly, leaving Luna to grab the magical objects inside the box: The Elements of Harmony.
Solar Storm - her former sister, Celestia - burst in behind her, only to see a rainbow glow coming from the room ahead. Luna turned around to face her sister, eyes glowing.
"You will not! Harm! Our! Ponies!" Luna yelled.
The Elements of Harmony fired, quickly hitting Solar Storm.
A white flash filled the room, quick dissipating seconds later. Luna looked around, but could see no trace of her sister.
She could feel a new connection, not just to her moon, but to the sun. Seeing as it was time to raise the sun, she gathered her magic and proceeded to do so.
When the sun rose, however, there was a clearly visible dark spot on it.
In the shape of her sister's head.
-=-=-
1000 Years later
Ponyville
Spring Starting Celebration
Luna knew this was the day.
The Elements of Harmony could only keep her sister entombed for so long. Even now, four comets were approaching the sun, ready, at the touch, to free her sister.
Earlier, she had received a note from her student, Twilight Sparkle. Had events gone differently, Luna was sure Celestia would have been proud to have her as a student, but alas, it was not to be. Apparently, her student had figured out the many clues Luna had left for her. She had sent her student to Ponyville as a result. After what would happen tonight, she was sure that her sister could be reclaimed.
Luna turned and looked across the throne room, where she had sat, every day, for a thousand years. Waiting for the day when her sister would come back. For the past five hundred, she had planned it. Her student, she knew, would eventually defeat Solar Storm, and her new friends, though her student didn’t know them as that yet, would help.
The Elements of Harmony would be restored.
[Two hours later]
Luna knew it was time. She had felt a massive magical force that she remembered from the time she had first banished Celestia, but it was different this time. Opening her wings, Luna took to the air.
Circling over Canterlot, she could see both the Solar and the Lunar guards patrolling the castle. Although Lunar guards were in abundance compared to the smaller Solar guard, she still maintained it, for the day when her sister would come back.
She flew over the landscape, quickly entering the Everfree forest to find to old castle, the place where the Elements had been stored. Quickly spotting it, she landed outside and stood by the door.
She heard the voice of the new Element of Honesty, Applejack, first.
“-Ah reckon we do represent the elements of friendship.”
Luna walked in, showing herself to the group. “You certainly do.” Luna said.
Her student let out a small gasp. “Princess Luna!”
Luna smiled. “Twilight Sparkle, my student. I knew you could do it.”
“But…” Twilight said in a low voice. “You told me it was all not real.”
“I told you to make some friends, nothing more. I knew the signs of Solar Storm’s return, and I knew that you had the power in you to wield the Element of Magic. But, you could not fully use it until you let true friendship into your heart. Now, if only another will.”
Luna turned around to see her sister on the floor, still almost as tall as her lying down.
“Princess Celestia.” Luna said in a loving voice.
Celestia gasped, and lowered her head.
“It has been a thousand years since I have seen you, and I think it is time to put our differences behind us. We were meant to rule together, sister.”
Everyone in the small group gasped. “Sister?!” They all said at once.
“Will you accept my friendship, Tia?” Luna asked.
Celestia jumped up and embraced her sister.
“I’m so sorry!” Celestia sobbed into her shoulder. “I’ve missed you so much, little sister!”
Luna smiled. “I’ve missed you, too.”
“Hey!” A pink pony, whom Luna recognized as the Element of Laughter, said. “This calls for a party!”
The other elements cheered, and they walked back to Ponyville.
Celestia chose to fly back to Canterlot, to start resuming her duties, such as raising the sun, which Luna gladly relinquished. Although she had managed to raise the sun this entire time, she was not the expert that Celestia was with it.
Her student, not surprisingly, had asked to stay in Ponyville, and Luna had granted her request. It was time to begin a new age.
The two sisters, Luna and Celestia, ruled side-by-side again.