There was once a little pegasus filly called Cadance.
Like many foals her age, she got really worried about getting her cutie mark, and like many parents, hers weren't able to help in any way other than say that it would come in time.
Cadance tried many things while looking for her own destiny, until one day she read a story about a beautiful magical jewel.
That jewel was called the Crystal Heart, and it had been created to unite the hearts of all the ponies in the Crystal Empire. The pegasus filly found that wonderful, and looked for every single story she could find about the Crystal Heart.
She learned in wonder about the group of artificers that had joined up in order to create it with the goal of ending a period of great strife in the empire. She read in excitement the account of the Crystal Heart uniting the entire empire to such a degree their combined power managed to repel the Spirit of Chaos, Discord. Her heart was filled with sadness upon looking at the story of the rise of King Sombra and his corruption of the Crystal Heart into a tool of domination over the crystal ponies.
Before Cadance realized it, her cutie mark had appeared, and it was shaped like the Crystal Heart.
Her parents were happy for her, even if they didn't realy understand what that mark meant.
Years passed, and the filly became a teenager. Cadance got a job helping manage the weather of their small town to get some money, but her most loved activities were related to the Crystal Heart.
She compiled stories of that artifact into a single book, she did little street shows where she told tales about it, she even did painting, sculpture and other art forms at an amateur level, just to create her own depictions of the Crystal Heart.
Still, the knowledge of the fate of the jewel haunted her, she had repeated dreams where she saw the Crystal Heart close by yet infinitely distant and impossible to touch, even thinking about King Sombra and his iron grip on the Empire and the Crystal Heart filled her with despair.
One day, things simply got to be too much. Cadance had become an older teenager, only a year or two from becoming a young mare, and she had spent half her life feeling helpless. The pegasus wrote a letter and mailed it to her parents, knowing this could be the last thing they ever heard from her. The contents of the letter were simple:
I'm going after my destiny.
Goodbye, I love both of you.
After that, Cadance flew to the train station and took a train to Rantail, which was the closest she could get to the crystal empire by train. She ate a meal in the town and got a lunch for later.
Then she flew in the direction of her goal, stopping once night fell, in order to sleep. She woke up, ate the lunch she had brounght and went back to flying, soon coming into sight of her destination.
It didn't take long for her to invade the airspace of the crystal empire, and soon many pegasus guards flew up to intercept her, but Cadance would not be discouraged by something so small. She simply accelerated and crashed through any pegasus that tried to interfere with her path. Her determination was so great that she was managing to force her pegasus magic much higher than she had ever done before, and even when the guards tried throwing lightning or shooting arrows at her, the magic in her body simply repelled them.
And then, after two minutes of flying at maximum spped, Cadance's will was strenghtened even further upon seeing her goal, the crystal heart, at the top of one of the castle's towers.
But things would not be that easy, because halfway in between her and the Crystal Heart, the air suddenly shimmered and there appeared the pony that had been the reason why Cadance had suffered so much over the years. The sorcerer unicorn, King Sombra.
"So, just a little pegasus and you were unable to stop her? You're going to be punished for this later." He spoke, his voice echoing all around.
He looked at Cadance with an expression of annoyance before shooting a spell at her, and the beam of magic was blood red and seemed to radiate menace. Every single instinct told her to dodge, but that would mean going farther away from the Crystal Heart. Even if she returned to the path later, Cadance felt like she would be betraying her determination if she let anything make her waver.
So she kept on her unchanging path.
The spell hit Cadance like lightning, she felt like her body was burning and her vision swam, but still, she remained on her unchanging path. This seemed to infuriate Sombra, and he charged a spell that was even more menacing, a dark sphere that radiated hate.
"Let's see how you'll fly without wings!" He shouted before shooting the spell at Cadance.
That was a terrifying curse that hit Cadance's body like a scythe. It was a spell specifically created to remove the wings of pegasi and make sure they would never fly again, and it had enough power to overcome three pegasi at once.
But somehow, Cadance wasn't immediately overwhelmed. Her determination to reach her goal had grown to such a degree that she brought out more and more magic from her soul, regardless of the fact that her body couldn't handle it. Cadance's muscles started to tear from the sheer excess of magic passing through them, her mind was suffering stress comparable to weeks without sleep, and her body started to feel more and more numb as the nerves died. And still Cadance kept resisting the curse, with the single-minded obsession of reaching the Crystal Heart, something she would give even her life for.
(I need my wings... To get there... I need... Do I really need them?)
And in that moment, Cadance's wings were cruelly severed, but she barely spared a thought to the notion of having lost an essential part of herself, as an instinctual manipulation of the wind via her pegasus magic kept her in the air and moving towards her goal, and passing Sombra's position. This was the only thing that mattered. Cadance felt that the only thing in the world was getting close to the Crystal Heart.
Sombra could barely believe that stubborn pegasus was still flying and had completely ignored his attempts at stopping her. His face darkened, and he decided to stop playing.
"COME!" He called, and there was no doubt about who he wanted.
Nightmare Moon, the slave alicorn, teleported to his side.
"KILL HER!" Sombra pointed at Cadance, and the corrupted alicorn turned and charged a powerful spell, that would never stop until the target was dead. It was a spell that put the entire being of the caster against the defences of the target, and as an alicorn, Nightmare Moon had an overwhelming advantage in that kind of struggle.
A purple beam lanced out from her horn with such violence that it felt like she should have been hurt by her own spell, and the attack reached Cadance without any possibility of being dodged.
Not that she would have dodged even if she could.
The killing spell hit the barrier of Cadance's will. The pegasus drew a colossal amount of magic from her soul to be able to face against the alicorn. In fact, she drew such an immense amount of magic, so recklessly, that it would be difficult to be certain whether it was the enemy spell or her own rampaging magical power that caused the most damage to Cadance's body.
Because it was her body that suffered, as couldn't be different when facing an actual alicorn. As the struggle went on, her muscles were ground like flour, her bones shattered, and the nerves burned, one of her rear legs fell off and her organs shrivelled inside her body. All that happened in less than three seconds as Cadance kept moving, and she was getting closer and closer to the Crystal Heart. The pain was beyond description, enough to break minds, but Cadance remained focused on her goal.
Yet, her body reached a limit, even if her will didn't. Cadance's nerves burned and she lost all her senses, keeping on her route only by focusing on the part of her soul that sought and resonated with the Crystal Heart. And then her heart finally stopped and her brain shut down, incapable of taking the strain.
Nightmare Moon's spell cut off, knowing that it was over, as Cadance's soul cried out from within the crypt of flesh her body had become, incapable of affecting the world any longer, separated from the world of death only by a thin line that was almost imperceptible. And yet, the last part of Cadance's consciousness that remained refused to give up, and managed to trigger a miracle.
The last cry of the soul, born of all the years of obsession with the object that was almost in reach, from all the understanding and her dreams about the power to connect people... It was heard.
Even though the Crystal Heart was under Sombra's control, a part of it remained that could hear Cadance's cry, and it responded.
It wasn't anything special, Cadance was losing altitude due to the stopping of her pegasus magic, and wouldn't be able to reach the Crystal Heart, but it pulled on her body slightly, changing her trajectory enough that her hoof just barely managed to touch it.
And then, Cadance's soul had a way of affecting the world again, even if it was limited.
The Crystal Heart was connected to every single one of the ponies of the empire, but Cadance's small bit of influence wouldn't be able to do much, so she choose only to transmit a few words to them.
"Ponies of the Crystal Empire, for long you have suffered under King Sombra. I have only one question to you all... In your heart, do you accept him as your ruler or do you reject him?"
Those words sounded on the soul of every single pony on the crystal empire, and before any of them had the chance to think about it, their instinctual responses were transmitted back to Cadance.
"I Reject Him."
The whole empire was united in that thought, and Cadance's soul channeled the power of that union in a way that could be compared to surfing a wave the size of the sun. All the rejection of the citizens of the crystal empire was fed directly to the Crystal Heart, and Sombra's connection to it... Was completely annihilated.
The magical feedback of that action hit sombra like a train, and he was stunned for an entire three seconds, and as such, was unable to interfere with what happened next.
A pure magic emerged from the depths of Cadance's soul, born from the sheer perfect expression of her destiny in what she had just done. But that wasn't all, that magic connected with the Crystal Heart, and from there with the hearts of every citizen of the crystal empire. The magic grew upon that connection, and then returned to Cadance's body, making a wonderful transformation happen.
Cadance's destroyed body was remade by the magic, every single part of her received the soothing attentions of that power and regenerated in ways that would be impossible even for the greatest healers in history. But that wasn't all, for Cadance's soul had changed significantly, and her changed soul meant that she needed to have a different body that would be in synch with it, same as the way her old body had been in synch with her original soul.
Cadance felt the substance of her body change, turning into something much more resilient and better at channeling magic. She felt her wings grow back bigger than they were before. She felt a horn grow on her forehead, a solid, powerful horn that felt like it could channel the magic of an entire world. And she felt countless other changes that she couldn't properly identify. Cadance opened her eyes, and saw that she had become an Alicorn.
It was at that point that Sombra recovered, and Cadance decided that she could leave self-examination for later.
"Sombra! Your end is now!" She shouted at him, then channeled the amazing powers of the Crystal Heart, which were now hers to command, and she was better able to use them than Sombra ever could.
Cadance didn't know any unicorn spells, so she simply channeled her desire to destroy the sorcerer unicorn into her magic, and created a wave of pure magic that barreled towards the false king with the inevitability of the rising sun.
But he still had something to rely on.
"PROTECT ME!" He ordered Nightmare Moon, who teleported in front of him and set up an spherical barrier.
The magical powers of Cadance and Nightmare Moon crashed on one another. Cadance wasn't using a proper spell and was a newborn alicorn, but she had the Crystal Heart as support, so they were surprisingly even. This could end up as a legendary magical confrontation.
But it didn't happen, Sombra ordered her to protect him, instead of trying to defeat Cadance. Nightmare Moon used the magical reverberation of the struggle to force her barrier, along with herself and Sombra, to take off and fly out of the crystal empire, and far beyond the reach of Cadance.
The new alicorn looked at the retreating figures and took back the magic of the now useless spell. Then she looked around and saw that many ponies had seen what happened, and more were coming out of their houses. A lot of the ponies were looking at her expectantly.
She was thinking about what to say when she felt something familiar in her new senses. Immediately, she talked through the Crystal Heart to ask the ponies to wait a bit, then she flew out of the crystal empire, and met two familiar pegasi, a stallion and a mare.
She smiled at them "Hello. Father, mother. I did find my destiny."
Her parents didn't know how to react to that, so they simply hugged their daughter, happy to see that she was alive.