One Blue Eye; One Green Eye

1,000 years ago on this day was the Summer Sun Celebration. it was also the day of Celestia's coronation.

Many years past was the day the past princess made her an alicorn.

A year later she made her sister the same as her. There was a reason she waited that long, although Luna didn't see it like that. To Celestia, she waited because of the thought of Luna outliving her friends, but did it because of the thought of having to bury Luna. But to Luna it was that Celestia had forgotten about her until then and was just remembering "oh yeah. I have a baby sister who wants to be an alicorn too."

But even after publicly naming Luna an alicorn, ponies still barely remembered she existed. And all through the years they ignored her and her night.

But yet Celestia was blind to it; to busy trying to run the country then listen to her sister. Celestia didn't even see how jealous her sister was of all the glory the solar sister got after defeating the tyrant Discord and the capture of the white dragonequs, Eris.

Eris had been taken to the palace after Discord's short, but terrifying reign. You see; back in those days it wasn't tall rabbits, chocolate rain, or buffalo ballets that were his style. Back then he was all about making a pony's worst fears come to life. And unlike normal dragonequi who could only make the illusion of fear; he could make it real, breathing, living fear.

Eris was not like Discord though. He had been a tyrant, but Eris was nothing short of a prankster that only created chaos for a good laugh. Simple as that. She had come into the land shortly after Discord, but unlike him the Royal Sisters spent no time waiting for her to start unraveling the sanity of ponies. Quickly they captured her and locked her away in an anti magic cell in the Canterlot dungeons.

Celestia was ready to turn her stone right away, but Luna had other ideas. They had been unprepared for the level of chaos Discord had created and if not for the Elements of Harmony they would have been defeated when they went after him. The sisters were lucky they survived the battle with Discord. Luna had the plan to study Eris, to try to figure out how dragonequs magic worked and why Discord had launched an attack on Equestria in the first place. And this might have been pony kinds only chance to really speak with dragonequi.

So, Celestia let Eris stay, but only if she stayed away from her and that she stayed in a locked room with an anti-magic ward on it. The sun princess was not taking any chances.

But after time went on Celestia started to realize how little she saw her sister anymore. Before they had been at least good friends and shared secrets no other pony or other creature knew. Luna had been spending all her time with that dragonequs. You see although Celestia was okay with Eris staying at the castle for Luna that was the only reason she was okay with it. If no for Luna there would be a new addition to the sculpture garden which wouldn't be too horrible. The garden was basically Celestia, Celestia, a fountain, Discord, and more Celestia.

So once when Luna walked off to Eris's room Celestia was with her. Using the excuse of "wanting to see Luna's progress on Eris." But of course Celestia hadn't learned that to be her name; Eris had always just been that white dragonequs to Celestia.

They walked into the her room and Celestia's eyes were wide. Instead of the normal and simple room their was a chaotic state. The dragonequs was sleeping on a cotton candy cloud and instead of having the books on the shelf they were flying around the room, narrowly missing the sun princesses head as she walked into the room.

Before Celestia could say a word about how this is not possible with the wards on the room, if the wards were still on the room? Eris sat up and looked from the Luna to her sister and with a snap brought the flying books to halt and sent them back to the bookshelf.

Oddly calm Celestia turned to Luna and asked, "What is going on Sister?"

Luna took a seat in a plush cotton candy chair and after spending a few minutes nibbling at the armrest she finally said, "Eris is completely harmless and We decided that she should at least be able to use her own magic." Luna left out the part about how the stability had almost killed Eris.

Just waking, Eris yawned and without opening her eyes or realizing Celestia said, "Will you stop with the Royal 'We', Lulu."

"And who are you talking to," Eris sat up and locked eyes with the glowering white alicorn. "Oh." Eris said and with that the books flew to the shelf and the cloud she had sat on turned back into a bed, as well as Luna's chair which resulted in a few holes in the chair and some coughing from it's occupant who had unwittingly eaten it thinking it wouldn't turn back to normal.

Ignoring the coughing and the frightened Eris, Celestia started again after Luna saying, "How dare you not tell me you loosened the wards. If a guard had seen the chaos they would have reported it to me and you know what would happen next."

Not knowingly Eris shuddered at the thought. But of course she hadn't known about Discord or what would have happened. Only that it wasn't good to anger a pony who could blast you with a solar flare.

...

Being inside the sun felt like were getting a warm embrace that was slowly strangling you. Fast enough that you knew what was happening, but slow enough not to feel it. Celestia would have been dead by now if not for the fact that every hour the cycle reverted back to the beginning and started all over again. The only good thing about it was that each day she could see the bright smiling faces of the ponies; and could keep a good eye on Luna.

Or the thing that was once Luna.

Now being in the moon was a lot different. It was like you floating in space, and could all around you. It was like you were inside a ball made of glass. Right in the middle of it so you couldn't break the sides. But instead of seeing only white in the sun, in the moon all you saw was the darkness and the distant flickering stars. You saw nothing of Equestria and your only companion was yourself, and your insanity. Or for Luna, her other half, her Nightmare Moon.

It was like she was in a hall of mirrors and in each one was Nightmare Moon laughing at her as that was what was happening only different. Instead of mirrors it was reflections of herself in the glass and instead laughing they talked.

Mostly the topic was Celestia and their plan once they got home to earth. Sometimes it was about the stars and how Celestia kept messing up when she made the constellations. But once in a while Luna would talk about Eris. When this topic rolled around Luna did most of talking, since for one Nightmare Moon wasn't around back then and two Luna was just talking to herself and did most of the talking anyway.

Luna had become Nightmare Moon on the anniversary of her disappearance and a year later after Celestia busted out of the sun she had been banished that day too.

Actually a lot of things had happened that day. Celestia and her had been made alicorns; notably a year apart. Eris had disappeared from the castle, her sister celebrated the Summer Sun Celebration, she had become Nightmare Moon.

And in turn been banished to the cold of her own moon.

...

Discord and Celestia stood near the base of what was once the west tower and what was now a giant pile of wood and stone. Using the newest princess and every unicorn at the party did the two immortals manage to at least re-build the base of the tower, they'd need Luna to finish the job off.

Panting and sweaty the two headed back the palace to discuss their newest visitor. Discord had been stone when Eris had been at the palace, but after hearing about how Discord was conscious when stone then he probably remembered when Eris had discovered what Discord had done and in turn what Celestia had done to him in return.

Celestia winced at the memory and remembered how surprised she had been when she discovered that Eris had not turned him into gravel, though when Eris had said she had dumbed down Discord's powers she now knew what that had meant.

Now he was just a prankster like Eris. Celestia shuddered, last time he had been a sadistic trickster who had nearly unrolled her sanity with the images he had showed her, of Luna, Luna...

Celestia's train of thought wandered off and together her and Discord walked into the castle. They made a beeline for the private guest rooms since Celestia and Discord's rooms were still firewood outside. Almost to the hall they were suddenly stopped by Shining Armor who had run up asking what he should do about the guests in the plaza who were asking a lot of questions.

"Send them home and say the information is still privy for the moment, but all their questions will answered," said Celestia wearily and with that the odd pair made their way up the many stairs.