Over one thousand years ago, Princess Luna was overcome by the resentment and bitterness she felt towards her sister, Princess Celestia. This is hypothesized to be the trigger that created Nightmare Moon. While many ponies believed this to be an old mare's tale, this ended up being the truth. After a terrible battle, Princess Celestia imprisoned Nightmare Moon on the moon for a thousand years, using the power of the Elements of Harmony. After the millennium of imprisonment, Nightmare Moon returned to Equestria, where the Elements of Harmony were used to return her back to her natural state as Princess Luna.
This is all common knowledge. I myself had a hoof in freeing Princess Luna from the darkness of Nightmare Moon, along with my friends. On top of this, over the years my friends and I have faced many foes. Each time we've triumphed thanks to the close bonds we share. We've faced nearly every threat to Equestria you could think of. From changeling armies to chaotic spirits with phenomenal cosmic powers. Despite all that I've been fortunate enough to accomplish, I never saw the most dangerous threat Equestria's ever faced coming.
My sister-in-law, Princess Mi Amore Cadenza. Better known as Princess Cadence.
Looking back on things now, I realize that the signs were there long before Cadence started to change. I've spent decades trying to pinpoint the event in time that triggered everything. For the longest time I thought that it was my battle in the past with Starlight Glimmer. That somehow, even though Spike and I were able to prevent Starlight Glimmer's plans, some small event changed. Maybe it was even just our presence that caused it. I believed that somehow, some way, something small changed, sending a ripple through time and space to alter events ever so slightly.
I've since abandoned that theory. Maybe it was the act of taking a pupil? Celestia has said that she'd had pupils as far back as the beginning of her reign. A student to pass knowledge to. Maybe, in some way, me taking Starlight Glimmer on as a student triggered some sort of recurring cycle. Some method of madness that time itself uses to mark important events. As I look over my research, I believe that this is the most likely explanation. The parallels that can be drawn between myself and Celestia, while in my opinion egotistical, can not be denied.
Both of us started taking on pupils. Both of us had a sister, by birth or law, slowly succumb to a darkness within them. Neither of us stopped it from happening either. And both of us even resorted to extreme measures to protect Equestria from somepony we never thought could harm it. Somepony we love.
The first sign that something was eating away at Cadence was a tragedy. I don't think anypony could have predicted it, but the miscarriage of her and Shining Armor's foal was devastating. I can only imagine what it must be like for an expectant mother to suddenly lose the life growing within them. Were it up to me, nopony would suffer that.
Cadence was devastated. She fell into a depression that nopony could help her with. Any attempts we made were refused. She locked herself away. She barely ate. I don't believe she really slept during that time either. She spent hours locked away in the library of her castle, pouring over tomes and long-forgotten books looking for some sliver of knowledge that would reverse what had happened. The other princesses and I tried helping in our own ways, but it was all for naught. There was no spell that could bring back the lost foal, and never has been.
During this time of mourning, the Crystal Empire began to decay. The Crystal Heart, the cornerstone of the empire, began to become corrupted. This was the first time we realized that there was something truly wrong. The Heart reacts to the emotions of the ponies of the empire. When Cadence was in mourning, it absorbed a large part of the negativity that she felt. Anger. Depression. Sorrow. Isolation. These emotions tainted the Heart. Even now, centuries after the events that transpired, what is left of the Heart reflects that negativity. Tiny spindles of black, akin impurities in a diamond, that coat the Crystal Heart like veins.
The Empire's decline was not pretty. It started economically. Citizens of the Crystal Empire lost the will to put effort into anything. Ponies stopped working. Shops closed down. It was as if the Empire itself were dying of some terminal disease. I suppose in a sense, it was.
Physical decay came next. The same impurities that formed in the Crystal Heart began infecting the earth itself. The tendrils of darkness grew through the streets. Houses started absorbing these roots as well. In the worst cases, houses simply collapsed; card houses with no support.
Ponies started to leave the Crystal Empire. The castle itself, a shell of what it once was, became a gray monolith. A memorial to what once was. A warning to what could be, elsewhere.
The next major blow to Princess Cadence came decades later. Her husband, and my brother, Shining Armor fell ill. Cadence spared no expense and assembled a team of the most brilliant medical minds from all across Equestria, from Hippo Crates to Doctor Redheart. Even then, Shining Armor's health decayed rapidly. Nopony truly knew what ailed him, though Cadence became convinced that the illness was treatable.
Whatever the illness, it started in Prince Shining Armor's lungs. From there it spread to other organs. Stomach, lymph nodes, even his heart. Small growths kept forming inside his body, and even with surgery it wasn't possible to stop the spread. Eventually the growths reached his brain. The end came quickly after that. At the age of forty-seven, Prince Shining Armor departed this world, having been survived by his wife, parents, and younger sister. The last words he ever spoke were "I love you, Cadence. Until the end of time itself."
Cadence became detached from everything after that. She withdrew from the public eye. Governance of the Crystal Empire fell to her advisers as Princess Mi Amore Cadenza isolated herself from the world. She took meals alone in her chambers. The only pony fortunate enough to see her, even briefly was myself. Even then it was only because I would bring her her meals, which often sat untouched.
This was the first point in which I became aware that Cadence was slipping towards... something else. I don't think I could have put a hoof on it back then. I'm not even sure I could now. But Cadence was definitely following the hoofsteps of some of Equestria's greatest foes. King Sombra and Nightmare Moon, in particular.
She became obsessed with time travel, convinced that if she could find a way to stabilize Star Swirl the Bearded's time travel spell she could go back and save her beloved husband. After years of trying to find a way to save her husband, Princess Celestia herself intervened.
"Even if you had the medical knowledge to save him, you cannot." She'd said. "I am sorry, but Shining Armor is gone. Perhaps some day you will love again. But if you focus on the past like this, I am afraid that you will never again look towards your future." I'll never forget the look of sorrow on Celestia's face. Or the look of betrayal on Cadence's.
It was the first time I'd ever seen Cadence angry. This was the mare who'd been my foalsitter. The mare who would unknowingly shape me to want to grow up to be like her. And at this point she was reduced to a ball of pure, unadulterated rage. In her anger, Cadence would exile Princess Celestia from the Empire and declare it a sovereign entity from Equestria. Her anger burned away the royal crystal empire library, along with a large chunk of the castle itself. She even crushed the Crystal Heart beneath her hooves.
The Crystal Heart had once been a relic of immense power. It acted as a sort of protection spell, amplifying positive emotions and transforming those into a way to protect the Crystal Empire from both outside threats and forces of nature. With the Crystal Heart gone, the perpetual storms of the Frozen North swallowed up the Crystal Empire. The few ponies that had refused to leave were lost to the cold, leaving Cadence the ruler of a cold and empty kingdom.
This was the final blow to Cadence. The one that broke her completely. She became convinced that there was nopony left to love her, despite my insistence to the contrary. I tried to tell her that I'd love her always, that the other princesses would be there for her too. She would always be my sister, even if Shining Armor was gone.
Bringing up the pain of losing Shining Armor ended up being a mistake. Cadence, under threat of physical harm, ordered me to leave her kingdom. After years of pushing everypony away and for the first time since losing her foal, Princess Mi Amore Cadenza was actually alone. The only living thing in the entirety of the Crystal Empire.
Two years would pass with no word from Cadence. I myself made repeated attempts to contact her during this time. She refused to respond to my letters. The only concrete evidence that she yet lived was the fact that she'd erected a barrier over the Crystal Empire using a combination of King Sombra's magic and the shards of the Crystal Heart. A gigantic pink bubble, undulating with ripples of black, sealed the Empire from the world, completing Cadence's isolation.
Then, after two years, the barrier would drop. Nopony knew why at the time, but Cadence was briefly spotted by the ponies Celestia ordered to watch the Crystal Empire. Reports were hazy, but many of the reports agreed that Cadence "looked different."
How different would be seen in Canterlot. It was there that she flew after leaving the corpse of the Crystal Empire. She would land at the entrance to the castle. She would be greeted by the royal sisters and invited in for tea. She would accept. And when the sisters had lowered their guards, She would attack.
The ensuing battle would nearly destroy Equestria. With her preemptive strike against Celestia and Luna, Cadence nearly killed both of them. The battle raged over the whole of Canterlot, despite attempts at avoiding this by the Sisters. The death toll was still in the hundreds, and damages to the city would take nearly three years to finish repairing. Many ponies are still amazed that Canterlot didn't fall from the mountain it sat upon.
Celestia and Luna managed to repel Cadence's attack, driving the broken princess from the capitol city of Equestria. Both of them were too injured to give chase, however. It was this point that Celestia would contact me.
I will never forget the letter I received that day. Nor will I forget the events that would transpire shortly after. Her letter was a warning. Cadence meant to topple the whole of Equestria. This meant the removal of every princess from power. Cadence had somewhat succeeded in Canterlot by putting Celestia and Luna out of commission for the forseeable future. It wasn't ten minutes after Celestia's letter arrived that Cadence would follow suit, landing upon the balcony outside my bedroom.
"Twilight!" Cadence smiled widely at me. It was the first time I'd seen her smile in years. With it came a flood of emotion that threatened to wash me away right then and there. "I know it's been a long time, but I wanted to see you. I've missed my best friend."
She knew exactly what to say to get me to hesitate. After Celestia's letter, I'd been expecting to be attacked on sight. Instead, I was greeted warmly, as if nothing had happened and Cadence just wanted to reconnect with the ponies she'd driven away.
Cadence, however, looked nothing like the mare she used to be. Everything about her appearance was different. Her coat, rather than it's usual pink, was a deep violet. Her mane, once a tri-colored thing of beauty with it's deep pinks, lavender, and golds, was now a deep shade of solid crimson. Her brilliant purple eyes were now a darkened indigo, and in them I saw the same darkness I'd seen when I had unkowingly begun my path towards becoming a princess of Equestria.
"Cadence? What's happened to you?" My voice was close to breaking. The mare before me was not the foalsitter who i'd wanted to grow up to be. "You look... different."
"That's because I am different. I've changed." Cadence gave me a genuine smile, which I found more terrifying than if she'd just let out a war cry and charged me. "I don't hurt anymore."
"What do you mean?" I asked, confusion added to the list of things threatening to overwhelm me.
"I found a way to fix my pain. Old tomes that survived the um, incident in the library back home."
I sighed. I knew what she meant, even if she didn't say it. Cadence had begun dabbling in dark magics, no doubt to find a way to reverse the pain she felt. After two years, the dark magic had overcome the poor mare.
"Listen, Cadence-" I began.
"Don't call me by that name!" Cadence lashed out verbally. "Cadence died with her husband. The mare you see before you is better than Cadence. I, Frozen Heart, have found a way to end the pain of the wrongs life forced upon Cadence." ~~Cadence~~ (I refuse to think of Cadence as Frozen Heart. As far as I am concerned, the two are separate ponies, much in the same way nopony thinks of Princess Luna as Nightmare Moon) Frozen Heart cackled.
"And now that I don't feel that pain anymore, I've come to avenge myself for all you did when I needed your help." Frozen Heart's tone was cold and even. What she said, in her mind, wasn't a threat. It was a promise.
"Ca- Frozen Heart! I tried to help you! I spent every day nearby, hoping to help in some way!" The wind began to pick up at this point. "I didn't do anything to-"
"Exactly! You didn't do anything! I spent years trying to find a way to fix things. And while I tried to solve the problem, you stood by and did nothing but talk!" Frozen Heart stomped a hoof, cracking the crystal flooring of the balcony she stood upon. Snow began to fall over Ponyville, despite it being the middle of Spring. "Now I'll make you regret your complacency." She sneered.
The ensuing battle would last three days. Three days of casting spells. Three days of arguing, trying to talk Frozen Heart down. Three days of trying to save Cadence from the darkness that had overcome her. Three days of tears.
By the third day, I'd managed to move the fight from Ponyville to above the Everfree Forest. We were both exhausted, but Frozen Heart refused to yield or retreat. Whatever drove the mare to fight refused to let her leave me be. By this point, Ponyville was buried in snow, the blizzard that had accompanied Frozen Heart being magically driven. The pegasi of Ponyville couldn't break the magical storm.
"Cadence, please. It doesn't have to be like this!" I pleaded yet again, my cries falling on deaf ears. "We can find a way to fix this. I want to help you!"
"Lies! Where were you when I needed you? Where were you when Shining Armor died?!" Frozen Heart screamed over the storm.
"I tried! I was there the whole time! I wanted to help, but we aren't Goddesses!" My tears froze to my muzzle. "Sometimes, even we have to accept that we can't fix everything! I know you're hurting. Believe me, when my brother died I was hurting too!"
"Then you should have done something! By not acting, you killed Shining yourself!" Cadence's attack hit me square in the chest, sending me plummeting from the skies above the Everfree Forest.
I can say, without ego, that under normal circumstances Cadence would have never been able to match me for magical strength. The darkness that gripped the fallen princess' heart also lent her a darker power, the same that held King Sombra in thrall. As I fell, I realized that this fight could only end in defeat. Mine. Or hers.
I hit the earth with enough force that I would have been killed, had I not had the power of an alicorn. Instead of dying on impact, I bounced. My body became a cannonball, tearing through trees until gravity proved to be the stronger force. Even then, I slid across the ground with enough force to create a shallow trench. I came to a stop in the ruins of a familiar castle.
The Castle of the Two Sisters was once the seat of power in Equestria. That was a thousand years before my battle with Frozen Heart. Now it stands as a grim reminder of Princess Luna's fall. The castle was worn, crumbling in some areas. Now, standing shakily after the blow from Frozen Heart, I realized that fate itself seemed to be telling me what came next.
I limped through the halls of the castle. Somewhere outside the castle, Frozen Heart was looking for me. I could hear her taunts over the winds of the storm raging outside, magically amplified to guarantee I'd hear. None of that mattered anymore. I needed to end things. Otherwise it wouldn't be just Ponyville that suffered. It would be all of Equestria.
It only took a few minutes to reach my destination. A small cave beneath the castle. Hidden away from the world was a force of nature that protected the world, a silent sentinel that spent countless eons standing guard. The Tree of Harmony. I placed a hoof against the pale white tree, housing six intricate gemstones that my friends and I had once wielded in order to protect the world. The Elements of Harmony.
"Found you..." Frozen Heart giggled. "Twilight, I'm surprised at you. Hiding in a cave like a frightened foal. I thought you were better than this."
"Cadence," I whirled around, pressing my back against the Tree of Harmony. "you can still stop this. Its not too late to prevent this."
"Funny. Those were the exact words I used on Celestia when I was trying to save my husband. Back then of course, I thought it was just Celestia being cold when she told me no. Now I can see that the words themselves are hollow. They mean nothing." Frozen Heart's horn began to glow as she charged a spell.
"Please..." I begged at this point. I knew what was coming. I'd seen it before, the day I ascended and became an alicorn. "Please, Cadence, don't make me do this." Cadence's horn glowed brighter as a second overlayer of magic enveloped her horn, quickly followed by a third. She was walking towards me, almost casually. She was humming something. Looking back, I think it was a nursery rhyme. She lowered her head ever so slightly, pointing her horn at me. I had no choice.
Reaching out with my magic, I tapped into the roots of the Tree. The effects were instantaneous. The Tree used me like a conduit, channeling the raw harmonic magics contained within the tree. Brilliant rainbow lights filled the cave, simultaneously blocking Frozen Heart's attack against me and wrapping her in a cocoon of magic. I remember watching this, like my mind had left my body to watch from the sidelines. The cave was filled with the sound of screams, though whether these were Cadence's or my own I will never know.
The rainbow energy that enveloped my sister, for that is what I truly consider her to be even now, shot from the cave, dragging Cadence with it. It stopped when it reached open sky, hovering in a perfect spherical prison. The light stayed for just a fraction of a second before shooting upwards into the sky.
I trotted outside the cave and looked upwards towards where the lights had gone. The sky was clear, with not one cloud remaining from the unnatural storm Frozen Heart had brought with her. A full moon shone down brightly upon me. Emblazoned upon the moon was the silhouette of a mare, strikingly similar to the one I'd seen every night growing up in Canterlot. It was too much to bear. I broke down into racking sobs.
Time is like a clock. It ticks on, never going backwards. Eventually though, the hands of a clock must strike midnight again. the same holds true for time. Eventually, the past repeats itself. Sure, the ponies and settings change, but the past will always repeat itself in some way.
I imprisoned my sister on the moon three centuries ago. Every night since then I've looked up at the night sky with tears in my eyes and repeated the same words. Two words that I hope, by some miracle, reach Cadence's ears.
"I'm Sorry."
Perhaps, one day, she will return like Nightmare Moon did. Perhaps things will play out the same way they did for Luna. And perhaps, just maybe, it will be my pupil who will be the one to play a part in it. With friends who will stand by her side, through thick and thin, until their last breaths on this world. I can only hope that this is the case. For Cadence's sake.
