Tirek stalked the dark streets of Canterlot, watching from the shadows for any unicorns foolish enough to wander down the alleyways alone and holding something in their aura. It was slow going, especially with all of the earth ponies and pegasi who insisted on walking around, and the few unicorns who were brave enough to venture into the shadows being aristocrats with nothing to carry, but he was making progress.
Time had very little meaning to a perpetual street predator like Tirek. He knew that it had been weeks, definitely a few months, possibly even a year or two since he had managed to escape from Tartarus. He knew that nopony was investigating the sudden loss of magic in so many unicorns, instead blaming it on various obscure venereal diseases that had been wiped out before he had even been sealed away. He knew that there was always somepony who, even if he couldn't steal their magic, he could still beat up and steal their food. He knew that it had been far too long since he had power, but he also knew that he need only be patient and ever vigilant.
And he knew exactly how he was going to use that power when he finally got it back.
Mulling over old grudges and elaborate revenge plans was one of the few remaining methods the decrepit centaur had of staying sane. The others had stopped working somewhere around the third hundredth anniversary of Nightmare Moon's banishment, or otherwise petered out over the course of his time spent huddling in dark alleyways and having to sleep through twice the amount of unicorns he did manage to rob. In a way, it made him relish his brief moments of victory over common unicorns all the more.
Thinking of that, Tirek looked up and spotted that most delicious of things, the glimmer of a unicorn's aura. He grinned so wide that you could almost see his toothy smile under the darkness of his hood, and he slunk towards his prey. This one seemed a prime catch; they were standing with their back turned to him, not making any effort to move away from the dark alley, and holding their carton of oranges almost ridiculously high above their head. It was almost too good a catch to be true.
Tirek wasn't the only one to think so.
Before the centaur could take another step, a shadowy figure leaped down from a nearby rooftop, landing on the unicorn and clubbing him around the ear before any attempt could be made to buck him off. As their mutual prey crumpled under the newcomer, Tirek had to fight down the urge to gallop over and wrestle with the shadowy figure. He barely had enough strength to carry a few buckets, much less fight off an assassin.
The shadow raised a hoof, and Tirek saw the meager light glinting off of a blade. He couldn't stop himself from crying out in shock as the blade came down, burying itself in the neck of the unicorn. He expected the victim to twitch and spasm under the blade, but the assassin was clearly an expert; the knife brought nothing but silence and stillness.
The assassin drew his knife out, and it disappeared into the shadows of his cloak with the click of a mechanism. He stepped off of the unico- the corpse with a practiced ease, and the edges of his hood glowed red with his own aura. Tirek's hind legs decided that they didn't want to deal with this particular unicorn, and began to try and drag him back into the shadows against the protest of the rest of his body.
"Tirek, I presume." The hood was flicked away, revealing a dark face with a flowing black mane that could have blended perfectly into their current environment if not for his glowing green-and-red eyes and his luminous blood-red... horn.
The horn that was still glowing with magic. The horn attached to a body that had just gone through an intense burst of activity. The horn that this stranger was practically waving in his face, his predatory grin giving away that he had no idea who he was messing with. Without any further hesitation, Tirek opened his mouth and began to drink in the magic.
The realization that his essence was being eaten did nothing to faze the stranger. Instead, he grinned all the wider. As his knees began to shake and wobble under him, he started laughing. As his face and body began to crumble into dust and disappear inside of Tirek, he just kept laughing and laughing and laughing.
By the time Tirek realized what was going on, he wasn't in control anymore. The unicorn was crumbling by himself, and rushing forward into the centaur faster than Tirek could close his mouth. Within seconds, the cloak fell empty to the ground, and Tirek's jaws were finally allowed to clamp shut.
He fell to his knees, his hands hitting the pavement, his lungs desperately trying to reject what they had been forced to swallow. There was a presence in his mind, someone trying to infiltrate his innermost thoughts and desires, and Tirek had no idea how to fight it.
"Who in the hell are y--ASSUMING DIRECT CONTROL."
Tirek's black eyes glowed green, and a self-assured grin designed for a more three-dimensional head spread across his face. "Please allow me to introduce myself," he announced to the empty alleyway. "I'm a stallion of wealth and taste."
Tirek looked around, confused. He was back in the cave, the cave where he had waited while Scorpan spied on the ponies. While Scorpan betrayed him. This was the cave where the ponies had come for him.
As if on cue from his memory, Tirek spotted a lone pony in a cloak wandering up the dirt path to his cave. Acting purely on instinct, he let the crackling power of magic build up between his horns, then he fired a vicious blast that should have torn flesh from bone and left the pony as nothing but a speck of ash on the wind.
All it did was tear the pony's cloak away.
It was a small relief to Tirek that the pony waiting underneath that cloak was not Starswirl the Bearded, or else one of the alicorns. But the pony underneath was far worse than them. It was the pony from the alleyway, except this time he was garbed in far more than a simple assassin's cloak. He wore a long, flowing cape of crimson silk trimmed with ermine, and bore a metal crown atop his flowing mane. There were bits and pieces of spotless armor all over his frame, and Tirek half-expected a sword.
"My name is King Sombra," the pony announced, suddenly standing on the threshold of the cave even though Tirek could have sworn he had been several feet away. "I am the sovereign of the Crystal Empire, the King of All Monsters, the nightmare from which there may be no waking. And you are?"
"I am Lord Tirek," Tirek proclaimed, the deep and booming nature of his voice surprising him. He had expected to still be speaking in the same reedy voice that he had been whispering to his victims in the alleyway. "Once and future conqueror of this pathetic sphere of existence."
"Wrong. You've never conquered anything." Despite being forced to measure up to a centaur stuffed with the memories of stolen magic, Sombra wasn't betraying so much as a hint of terror. "And you don't want to conquer Equestria. You want to destroy it."
"What's the difference?"
Sombra glared at Tirek. His horn glowed, and the stones of the cave broke apart and fused together to form a blade. Without even blinking, he cut off one of Tirek's arms.
"A conqueror leaves something standing. Ponies, buildings, some vestige of what a place used to be before he swung through. Take me, for example. The only part of the Crystal Empire I ever destroyed was their free will." Sombra's stone sword slashed again, this time merely tearing a huge gash across Tirek's chest. "A destroyer leaves naught but ash in his wake, if he's generous."
"So, you're tearing me apart because of semantics?" Tirek tried to prepare another spell, but Sombra simply leaped up into the air and cut off the centaur's head with a single fluid motion.
The fact that Tirek kept being able to think and speak diminished the gesture a little, but it was still quite a shock.
"No, the tearing you apart is for much better reasons. Celestia's reasons."
Tirek's head laughed, even as the motion sent it spinning through the air. "Oh yes, because I'll believe that! You just told me that you conquered an entire empire and took away their free will, and you expect me to believe you're working with Celestia?"
"I don't expect you to believe anything, Tirek. But it's the truth. While you were in Tartarus, the world changed. Old enemies resurfaced, and were defeated. And Celestia realized something, with my help."
"And what did she realize?", Tirek sneered.
"That there will always be evil, but there won't always be villains. A villain is someone with an ethos that is in opposition of good, an opposite number that seeks to overwhelm and change the world as it is. A villain can be fought, can take part in wars, can take centuries to defeat. A villain has a place in the world, and can eventually find balance with a hero. But there are some creatures of evil, monsters, that seek to destroy everything."
Sombra's blade slashed through the rest of Tirek's body. "A monster cannot be reasoned with, will not listen to negotiation. A monster has no halfway point, no system of restraint, no ethos, no beliefs. All a monster has is the desire to make the entire world as empty as he is. Tirek, you are a monster."
"So you just decided to kill me? All of your own accord?"
"Oh, no." Something approaching a genuine smile flitted across Sombra's face. "If I had my way, I would have hunted you down and publicly gutted you the moment we found out you were loose. It was Celestia's idea to let you have hope that you might win."
"Why in the blazes would she allow that?" Tirek demanded, his body fighting to re-assert its natural shape.
"So that you would know what I bring to the table." Sombra brandished his sword, more to look fancy than anything else. "Because my subjects have hope. They live under a tyrant, but they have hope. Because they know that if they were in danger, they would already be dead. They hear rumors of a rebellion. And they know that if they could just run far enough, and fast enough, they might reach Celestia."
The sword flicked through the air and cut Tirek's head in half. His mouth stopped working, but his brain kept going so that he could still listen.
"But there is no hope of an escape from Tirek, because everypony who doesn't run from Tirek only makes him stronger, lets him chase faster and harder. And there's no safe place to run to, no place that will stay safe, because eventually he'll eat the alicorns when they fight him and we'll all burn and die." Sombra's blade crumbled, as did the world.
Back in the real world, Tirek gave a final, violent cough. Sombra came leaping out, assembling from dust and springing into glorious full regalia. He turned and sneered at the centaur, who had only a few seconds left before his lungs collapsed and he got dragged down to Tartarus through the one-way passage.
"I am stronger than you because I can be beaten. Because there will always be someone who can. I can survive in a sane world, but you? You cannot be left to sit and grow stronger in distant lands. You and your kind demand a hunt, a quest with a timer. And that is why you will always lose."
Tirek died. Sombra walked away. And Discord got up and had a horrible coughing fit.
Author's Note
In short, Sombra for best villain.
