Celestia opened her eyes with a groan, her entire right side flared with pain that she had never experienced before in a thousand years. Though her consciousness was jaded and her vision was blurry from first waking up, the princess of the sun knew in an instant that something was wrong and she shouldn’t be feeling like shit. Groaning and struggling to get her consciousness back to her, Princess Celestia brought up a forehoof to her head to massage the pounding head pain she was feeling beating against her skull like somepony was taking a hammer to it. It was not a pleasant feeling to be sure and she knew it wouldn’t get any better once she finally got up.
Her skin and coat met cold metal that she would associate with her royal horseshoe yet somehow, wasn’t that at the same time, a strange combination. A thought passed through Celestia’s head that screamed something was wrong that the eldest princess tried to ignore as she continued trying to wake up, however the screaming in her flared gut was hard to ignore as Celestia wouldn’t be feeling this much pain if she was fine. The white alicorn shook her head hard, trying to clear her vision so she could see better. Her eyes shut as bits of her starry mane hit her eyelids then reopened them to see where she was, it was a familiar sight for she had been here for the past thousand years before she moved into a different place.
She was in the Castle Of The Two Sisters, the same place she had gone to when her sister, Princess Luna/Nightmare Moon, returned from the moon after the stars aided in her escape. Her memory was rather foggy, but the princess of the light faintly remembered confronting her former beloved sister in the abandoned throne room, the blue green of Nightmare Moon’s eyes glowing in the darkness of the beautiful night she brought with her. The glowing yellow and blue green lights from their horns lighting the night brighter than the moon itself in the sky. Looking back to the hall where her faithful student, Twilight Sparkle, along with her new friends, Rainbow Dash, Fluttershy, Rarity, Pinkie Pie and Applejack, were meant to go up to retrieve the Elements Of Harmony.
When her student didn’t come to her rescue, Celestia’s horn glowed brighter yellow, a spell that she found in the new castle’s library when she and Twilight went on a reading spree, being poured into her magic, ready to end this and free her sister once and for all. Nightmare Moon’s eyes widening, a panicked look that didn’t look right on a villain of Equestria almost like she knew what that spell was and what was going on. What happened next was a total blur as she found herself against one of the walls of her former castle, but Princess Celestia had a bad feeling that the spell’s effects had not gone the way she expected or hoped.
The princess had no idea what had happened or what could’ve gone wrong, but she had a bad feeling that she would find out in a few seconds. Those were the few seconds she dreaded the most but simply lying on the ground against a wall was only going to make the feelings of dread and uncertainty worse, might as well just get the bad news of what had happened done and over with. The world became more clear as the sun princess’ consciousness finally returned and with it, the pain grew stronger to the point Celestia almost passed out again.
However, by some stupid miracle or curse, she didn’t and she struggled to get on her hooves, her golden horseshoes dragging along the ground. As her hooves found the floor, two things caught her reddened bloodshot eyes and made the soft flowing dread suddenly over drove into panic and adrenaline that awoke the rest of her senses and made the pain almost an afterthought. Celestia was met by the familiar gold of her royal shoes as she stared at her hooves, but with it came the unfamiliar light bluish purple of an armored hoof covered by deep black fur that the white alicorn knew didn’t belong to her.
Her eyes widened in horror, her hooves nearly giving up on her as she scrambled back from the sight that she knew was the cause for all this pain but she needed more confirmation even if she would have a heart attack. Light blue and purple met Celestia’s eyes as her mane flowed in front of her, though her normal colors were there as well, she recognized the other colors. The denial as to what had happened was screaming strong inside Celestia’s head, another part of her was telling the spell had failed her unfortunately.
She wasn’t sure how she knew or what part of the spell had backfired on her, but instincts the alicorn never knew were inside her told her she should’ve banished Nightmare Moon back to the moon, gotten Twilight and the other chosen Elements Of Harmony to pure her sister, anything rather then dive into spells that were forbidden for damn good reasons. Celestia struggled to light her horn with her magic, bluish-green mixed with yellow met the dark room and her eyes, another fact as to what could have possibly happened. But there was only one way to know for sure even if she didn’t want to see the image of what she had created.
Though her legs were wobbly, the princess took a look around the castle before she bolted upstairs to her former bed chambers to the nearest mirror in sight to find the final confirmation. Her metal, armored horseshoes clanked the floor as she ran, her mane fluttered behind her, the pain grew stronger feeling more like a hot fire like her skin had engulfed her skin. However Celestia paid it no mind as the light from her horn finally lit up and reflected the image of herself as she came closer to it, the single mirror she had set up in her bedroom met her face.
The surface was cracked but Celestia could still make out her face, not just hers but also Nightmare Moon’s. As the alicorn looked on, she realized with horror that the spell had turned her entire right side into the mare in the moon like one of those split pony paintings except there were a few more details on her own painting. Crusted crimson blood ran a line down the split where the two were connected almost like a set of deep red stitches. A layer of rust ran along their armor connected together, their horns curved and warped but was still able to cast magic if the light at the top was any evidence.
Even if the light was dim, Celestia could still see her combined image that she thought only existed in a nightmare but was now real. Twilight and her friends flinched when they heard a scream from downstairs in the throne room where Twilight’s mentor, Princess Celestia was waiting to face down Nightmare Moon, hoofsteps then followed as they ran upstairs toward the source. Their own screams filled the Everfree Forest as they laid eyes on the new monster in the castle: Nightmare Light.