Five Years into the Future...
Canterlot, Evening
Canterlot, the former capital of Equestria, rested peacefully under the magical shield under the half-day half-night sky. Inside the sphere of magical energy, the world was a happy, cheerful place. Outside it, it was a ruined, burned down wasteland.
Big Macintosh had just finished his daily rounds around the still-intact city; as the Captain of the Guard, it was his duty to ensure the safety of it's citizens, as it was currently the only known city in Equestria still in existence.
The last five years has been chaos for the kingdom; The Princesses were gone (which explained the status of the sky), countless lives had been lost, and cities had been reduced to little more than rubble, starting with Ponyville on that fateful day five years ago. The fiend, known as Dark Spark, that caused all of this had been only kept out of the city thanks to the unicorn guards who renewed the shield spell every twelve hours.
"Squad Leaders!" His voice boomed as he entered the former throne room of Celestia and Luna. Immediately, the three soldiers, each of the three pony races, who had been playing cards and goofing off snapped to attention. They knew better than to tick off Captain Big Mac, who had brought it upon himself to defeat the Enemy. It was hard to believe he used to be a quiet farm pony of few words.
"How're the skies, Ray Shine?" he asked the Pegasai Guard.
The leader, who had shed his helmet to show off his orange coat, sky blue eyes, and yellow hair, saluted. "No interference from the sky crews; weather's running fine as usual, sir; nothing spotted from above."
"At ease." The pegasus sat down. "How's the civilians and food doin', Green Donut?"
A green Earth Pony with purple hair, orange eyes, and freckles saluted. "Produce and water levels are stable, sir. Civilians had a practice drill a couple weeks ago if Dark Spark will show up, sir. I must warn you, sir, that the civilians are getting restless."
"What y'all mean by that?"
"W-well, sir, there are rumors going around that Dark Spark has a plan to break through the barrier-"
"Hold on just a pony-pickin' minute here!" The soldier immediately clammed up under the withering stare of Captain Big Macintosh. "Them rumors have cropped up faster then weeds over the past five years an' keep comin' back no matter how fast y'all pull 'em! The barrier is still standin', right, Shield?"
The gray unicorn with silver eyes and black spiky hair, whom the question had been adressed to, nodded. "Yes, sir. The barrier was just refreshed an hour ago, sir."
"See, Green, there's nothing to get yer mane in a tangle 'bout."
The Earth Pony kneeled. "Yes, sir. Of course, sir. I'm sorry, sir."
Big Mac kneeled down and gently stood his soldier up. "Don't look like that, Green. You're okay. I just don't wanna let paranoia get to you. First round of cider on me?"
All three of the Squad Leaders perked up and nodded, heading for the door with their friend.
Suddenly, a screech sounded and a magenta light appeared behind the four colts. All of them turned back and saw a shadowy figure, with the only thing visible being cat-like eyes with irises as red as blood.
"Hello again, Captain Macintosh," A low, monotone, and creepy voice said. "I see you got some friends with you."
The squad leaders stared in shock. Big Mac, on the other hoof, just grunted annoyingly.
"You again?! I don't care how powerful you are, Dark Spark. We both know this is just an astral projection, and we both know you can't shatter the shield!"
"Until today." The projection disappeared.
"What the heck was she talking ab--" Ray Shine's question was cut off by a sudden massive, shriek ripping through the air, literally. Sonic waves of violet ripped through the city.
All four soldiers covered their ears as their eardrums throbbed horribly. All around them, glass shattered, buildings collapsed, and civilians were blown away.
The blue shield slowly cracked. Big Mac silently pleaded for it to hold, but it was in vain. After ten seconds, the wall of protection broke, giving way to destruction.
In under thirty seconds, violet blasts of light tore up half the city. Most of the ponies didn't even have time to scream before they were made into a bloody mess. The pony of mayhem flew up to the balcony where the four ponies stared in horror and got a good look at Dark Spark.
She was a head taller than them, with a violet coat and pointed unicorn horn, red cat-like eyes, fangs, nicked ears, and a matted mane and tail of indigo and magenta. She sported a black body suit with a cape and solid gold shoes.
"Like the new spell? Star Swirl the Bearded is the only other pony besides me to pull that off. He called it the Scream of Destruction. You gentlemen are witnessing history; the reemergence of an ancient spell, and the Great City of Canterlot being destroyed." She glowed her horn and made the castle collapse in three seconds flat with a wicked smile. "Too bad none of you will be around to tell the tale."
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All of this was being watched in a scurrying bowl by a unicorn with tan butterfly wings. Tan and jade green made up her coat colors, with an open book and a quill writing on it as a cutie mark. Her white mane and tale was done up in a bun, and her small reading glasses were perched over her scrutinizing gray eyes.
"You see now, Bookkeeper?" The old grandfather clock said behind her. He was twenty feet tall, painted purple, and had purple eves in the face of the clock.
"Yes, I think I get it; Twilight Sparkle, the Princess of Friendship, grows up to become the most evil pony in Equestria." She turned to her master. "What do you want me to do?"
"Isn't it obvious? In order to save the future, Twilight Sparkle must die! You must kill her!"