An incredibly powerful storm had been brewing over Ponyville for a long, long while. Many residents were too busy thinking that one wasn't scheduled, but prepared anyway. What none of them knew was that this storm actually marked the return of an incredibly powerful foe.
But, because we aren't counting Celestia or Luna as "Ponyville's residents", they knew full well what this storm heralded. Both were quickly scratching down letters for Twilight, telling her to disregard the storm, and come to Canterlot. The letters were sent out when they were both eventually finished, and now all that was left to do was wait.
Though, since the storm was exponentially growing, it would only be so long before it reached Canterlot. "Please, hurry?" Celestia pleaded.
The crystalline castle that served as Twilight's base of operations was inherently sturdy thanks to its main building material. Didn't stop Twilight from preparing a rudimentary survival kit if worse came to worse. "Alright, we have toothbrushes, toothpaste, some non-perishables, and my literature. Is there anything else we need?" She asked Spike, looking over a checklist littered with scratch marks hiding unneeded materials.
Spike didn't get a chance to respond, as a letter came from Celestia, forcing a burp yielding green fire and a scroll. "Non-prescription medicine! Of course!" Twilight interpreted, seeing it as a sign for antacids.
"No, you got a letter." Spike clarified, waving the scroll in Twilight's face. Rolling her eyes, but still throwing in some aspirin from the medicine cabinet, Twilight opened up the scroll.
Twilight,
A storm of this nature is not natural by any means. Come to Canterlot as soon as possible, and see if your friends can come along?
Celestia
How concise, Twilight decided before looking over the survival kit. "I think that's everything." Twilight decided before levitating the letter over to Spike so he could get a glimpse. Spike didn't respond verbally, just pointed at the door.
Everyone had the same idea she did; go into Applejack's cellar and wait out the storm. One could imagine the shared disdain when Twilight said she wanted Celestia to have them go to Canterlot.
"Are you serious, Twi?" Applejack deadpanned, her hoof holding her face.
"Look," Twilight started. "It's been a while since this happened, this must be very serious." This reasoning was greeted with some rounds of approval, but a more pressing matter was at the forefront of Rarity's mind.
"How are we going to get there in this weather? The train's halted, and the weather speaks for itself." Twilight merely flexed her wings before Rarity responded with a quick, simple, "Ah."
Twilight illuminated her horn, preparing for a mass teleportation to Canterlot. While it did go through, she was exhausted by the time she reached the castle's doorstep. Applejack hefted her up onto her back and let her pass out for a spell.
"You summoned us?" Rarity asked upon finding Celestia's whereabouts in the throne room. Applejack set the still-unconscious Twilight down on the stairs to her throne.
"Yes, the storm in Ponyville is not a scheduling error." Celestia explained. Rainbow scoffed behind everyone, muttering something about "never getting the memo." The Diarch of the Sun disregarded Rainbow's snark, railing back onto the more pressing matter. "Something of this nature can only be the work of a returning demigod from Tartarus." When she received no response after that phrase, she halted, looking uncomfortable. "You... HAVE heard about the legend of Demon Bash, right?"
The 5 fully conscious Ponyvillians looked around at each other before collectively shaking their heads. The still-woozy Twilight managed to garner the strength to fill them in. "The summary is that he was the ruler of Tartarus and wanted to expand his land further. You probably can infer how that turned out." She popped an aspirin from the survival kit she still had with her into her mouth.
"That was about 5000 years ago; give or take a couple of centuries." Luna expanded, making her presence known while shaking her hoof.
"And dare I say, it's good to be back!" A voice echoed from all around them before a red-and-black fire burst behind everyone. The flames dissipating, unveiling the alicorn responsible for the silhouette.
He had dark red eyes with slit pupils, one of which was hidden behind his mane of alternating jet black and the same shade of red. On each of legs were spiked collars, as well as one on his neck. His wings were not traditional, as they looked more like a bat's wings. His tail had the same color scheme as his hair, only heavier on red as opposed to his mane's focus on black.
No one in the room could take his appearance seriously.
Rainbow fell out of the air onto the ground, slamming her hoof in fits of laughter. Fluttershy and Rarity were both trying to hide their snickers behind their hooves, though neither of them were doing very good. Twilight at first took him seriously, but she then realized how dark and edgy he looked. Applejack held her hat over her eyes, trying not to break down. Pinkie Pie always appreciated a good joke, and now one was ponified for her!
The diarchs would have taken him seriously those many millennia ago, but now that other threats have been toppled, neither was able to contain their snickers."You dare to laugh at me?" Everyone in the room, except for him, broke down cackling mad.
Through the tears, they barely managed to get out their apologies. "RUN!" Spike mocked. "He's had 10 squillion years to consider his revenge!"
"He's not that old!" Rarity played along.
"Well it's some stupidly large number, make any potential onlookers side with him!" He howled.
"What is this mockery?!!?" The darkest alicorn stared, causing everyone to break down once again.
Rainbow tried to play it straight, but she was barely able to finish the sentence before she broke down. "You're what every hormonal colt thinks he can be!" She fell back down, still cackling mad.
The point got across incredibly quickly. Demon decided that maybe a place as saccharine as this wasn't to his liking. As such, he decided to trot out of the throne room and maybe find some other area to deal with.
Upon leaving, a cadre of guards ambushed him, pinning him down in a chokehold that kept him from using any sort of magic. "This wasn't diplomacy."