Many thousands of years ago, the frozen north beyond Equestria, was an empire.
Many ponies wonder why in the world anypony would want to create a civilization over there. The ground was too frozen to grow anything and the air was freezing no matter what the season. Other ponies argue that the first rulers probably built it there for the privacy. After all, who in their right mind would go someplace like that for a holiday?
The real reason, however, was kept a secret for generations. Even the citizens of the Empire weren't sure why their home was located where it was. The question could easily be answered with one word:
Crystals.
Miles underneath the ice, hundreds of magic crystals lay far beneath the surface. As the first rulers of the Empire were Earth Ponies, they had a special connection to what lies under the ground and claimed the frozen wasteland above as their own. They built a beautiful city made purely out of the crystals mined from under the ice and the ponies that lived there flourished.
The magic in the crystals formed a protective shield around the Empire that kept out the cold, icy winds and allowed crops to grow while the ponies were able to secretly live in wealth.
More stunningly, as the ponies lived in the Empire, it was noticed that their coats took on a brilliant shine, as if they themselves were made from the crystal that they lived in. The crystalline ponies of the Empire became known as the Crystal Ponies.
As word about the mystical Empire spread, ponies were amazed and baffled about it's secrets and many attempted to discover how everything worked there. The rulers, however gave nothing away. The Empire became known as the Crystal Empire, the land of unlimited riches.
The race of Crystal Ponies were always Earth Ponies. No Pegasai, nor Unicorns ever were a part of their race. That was, except for the Royal Family.
At first, they were all Earth Ponies, like their subjects until somewhere along the line, a Crystal Princess was married to an Alicorn Prince from Canterlot, Prince Isaiah. He became the very first Crystal Alicorn, and the most powerful pony in most of Equestria, save the two regal Alicorn sisters of Canterlot, themselves.
The Crystal Ponies discovered that over time, their bodies had absorbed some of the magic in the crystals that their Empire was built on, resulting in some ponies having strange powers that were usually uncontrolled and extremely hazardous. To prevent anything drastic from taking place, King Isaiah and his Queen, Ruby created an object called the Crystal Heart.
This artefact was a turquoise crystal carved in the shape of a heart. It was powered by the magic inside the Crystal Ponies and was used to spread peace and tranquility across not only the Empire, but Equestria itself. A fair was held each year to renew the magic that powered the Crystal Heart for the many years to come.
After over a hundred years of ruling, King Isaiah and Queen Ruby eventually passed away, leaving the Empire in the hooves of their only son, Prince Diamond Heart.
Diamond Heart was a wise Pegasus (the first one to be of the Crystal race, in fact), but whenever he was faced with a problem he could not answer, he usually panicked that his wisdom wasn't as good as he thought and would try to take matters into his own hooves. When he married Princess Rin, a Unicorn from Saddle-Arabia, he had one of his panic attacks before the wedding ceremony.
And when Queen Rin had their foals, he had yet another panic attack.
King Diamond Heart paced around his study, his moves clearly edged with agitation as he awaited the arrival of his children. Now that it was happening, he could suddenly think of hundreds of things that could go wrong and was praying that none would.
His wings flapped with anticipation and the guards in armour made from the Empire's magic crystal had to back away to avoid being hit by his massive wingspan. The crystal that made up the armour made it stronger than any metal, something very useful when at war.
The king stopped pacing as the doors swung open, revealing a relieved-looking young mare in a white coat. Before she could say anything, the king hurried up to her.
"Is my Rin alright? Can I see her?" He demanded.
The mare took a few steps back, unused to being spoken to like this by her king, "She's fine." She told him, "She's just a bit tired. You can see her, but..." She hesitated.
"What is it?" King Diamond Heart demanded, the feelings of panic flooding back, "What happened, did something happen?"
The nurse held up one hoof, "You might just want to calm down a little before seeing her." She told him, "There's nothing wrong with your queen, it's just..." She paused again, thinking of a way to put it, "One of your children may appear slightly... Different."
Diamond Heart didn't care, all he wanted was to see if Rin was truly alright, "I don't think that matters too much." He told the mare, "May I see my wife now?"
The mare dipped her head and led the king out the door. But the moment they left the study, Diamond Heart sprinted ahead, straight to his and Queen Rin's chambers.
He found Rin lying on their large bed, looking tired but happy. Two young foals were curled up against her; a pale blue Pegasus filly with a darker mane and a silver Alicorn colt with a white mane. The two foals dozed peacefully against their mother's flank and Diamond Heart gave a sigh of relief, everything was fine.
Careful not to wake his sleeping children, he made his way over to the bed and sat down beside his wife, "Are you alright, darling?" He asked quietly as he stared down at his children. What had the nurse meant that one of them was different? The both looked perfectly normal to him.
"I'm fine." Rin breathed, nuzzling his chest, "We've got two perfect foals, what shall we name them?"
Diamond Heart stared down at he two newborn ponies for a while, carefully deciding on the names. "How about we call the filly Lucida?" He suggested. It sounded like the perfect name for a princess.
Rin smiled at him, "I love it." She breathed, exhausted from the past hour, "Can we call the colt Pluto? After the Alicorn god of wealth in Romare mythology."
"How fitting." Diamond Heart told her, pride rushing into his heart as he looked down at his and Rin's children. As he did, he forgot all about the nurse's ominous remark.
It wasn't until three days later when the white coat-clad nurse came to her king once again that he found what she had meant.
"I'm very sorry to bother you." Diamond Heart looked up from his paperwork to see her standing in the doorway.
"No worries." He assured her, pushing his papers to one side to show that she had his full attention, "How may I help you?"
The mare looked slightly wary, "Well, since a bit of time has passed, we think that it's time to show you and your wife something. We thought that maybe we should let you settle down a bit before we showed you."
Her words instantly filled Diamond Heart with panic. What could it be? It had to be bad if it was something that even the Royal doctors were hesitant about showing their own king. "Alright, very well." He said, forcing himself to look calm and professional, "Please take me."
This time, it was Diamond Heart who lagged behind as the nurse led him through his beautiful crystal palace. The guards carried on like they normally did, unaware of the tension in the atmosphere. Even they must have not known of the mysterious secret that the doctors were sharing.
They made their way up the staircases made from quartz, gradually getting higher and higher up until they reached one of the highest and most secluded towers in the palace. By then, the king was really starting to worry. What could be so bad that it had to be actually hidden in one of the most remote places?
As if she had read his mind, the nurse quickly said, "We weren't sure what you would think of it, so we took it here for one of your maids to look after. We decided to wait a while for you to get over your worry for your wife before showing it to you."
Before she could open the door, it swung open to reveal a slightly flustered-looking Rin. "Darling, I think you should have a look at this." She told him, beckoning for him to enter, "In all my years learning magic, I've never seen nor heard of anything like it."
Cautiously, Diamond Heart stepped into the room. It was small and round, with only one window that gave a view looking out across the west side of the Empire. A maid by the name of Ella Care was standing protectively beside a bed on the other side of the room, but she stepped aside to let her king see what she was defending.
It was a Unicorn colt, it's pelt a dark grey like ashes after a fire with a darker stripe down it's nose. It's mane and tail were as black as sin and when it opened it's eyes, Diamond Heart recoiled in horror. It's irises were as red as blood and it's pupils catlike slits. Along with that, it had long, sharp canines, like fangs protruding from it's mouth.
"King Diamond Heart, Queen Rin, this is... Your son." The nurse said, her voice hesitant.
Diamond Heart stared down at it in shock, "My son?" He asked. What was with it's pelt? It was so... Dull. No matter what, every pony with Crystal Pony blood that was born in the Crystal Empire always had a shimmering pelt.
There was a long pause as the ponies in the room before the nurse asked in a very quiet voice, "What are you going to do with it?"
She shouldn't have said that, it was a question that her king didn't know the answer to.
What should he do? There was no way in Tartarus that he was going to present it to the Empire as his son. What would the Crystal Ponies think of him then? It's siblings may hate it and make it's life miserable. He couldn't kill it, he didn't have the heart. It was a living and breathing creature, it didn't deserve to die, no matter how abnormal. He could give it away, put it in an orphanage somewhere. Yes, that was a reasonable option. The young colt wouldn't remember that he was supposed to be a prince. He could leave it in an orphanage of a highly populated city, like Manehatten. They would be used to strange ponies there.
"It might just be a phase." Rin said, her voice breaking through Diamond heart's thoughts, "Maybe his appearance would change back to a normal ponies' when he get older?"
Diamond Heart considered this. He could take a gamble and keep the grey Unicorn colt in hopes that it would grow out of it's appearance as it ages. However if he did that, he wouldn't be able to put it in an orphanage as it would remember living in the Crystal Palace. He wasn't sure which outcome would be crueler. He was supposed to be the wise, loving king of the Crystal Empire. If anypony found out about any of this...
"We'll keep it." He decided at last, "Rin may be right, it's appearance may change when it gets older."
"He." Ella Care said.
Diamond Heart frowned, he was rarely spoken to like that, "I'm sorry?" He asked the maid.
"Your child is a 'he', not an 'it'." Ella told him, "Stop referring to him as 'it'."
"Ella." Said Rin gently, "We may not even be sure if this thing is a pony."
Ella glared at her queen, "Of course he's a pony!" She exclaimed, "Both his parents are ponies, why can't he be?"
"Show some respect when you speak to your rulers." Diamond Heart warned her sternly, "You're a maid, not an advisor." A thought suddenly occurred to him and he added, "Since you appear to have some sort of empathy to this thing- Unicorn, why don't you look after him? My Rin will be too busy looking after little Lucida and Pluto."
Ella Care thought about it for a heartbeat before bowing, "I'll be honoured." She told them. As the king, queen and nurse began to exit the room, she called, "What will you name him?"
"Sombra." Diamond Heart called without looking back, "It means shadow."