Thunder crashed and the tiny space where Nightmare Moon appeared filled with dark clouds and an evil laugh, “Bwahahaha, behold I, Nightmare Moon, am retu- wait what in the hay is this?” Nightmare Moon flapped her wings and settled the clouds so she could see the hard clear surface in front of her.
“It’s a glass mason jar with some holes in the lid,” answered a bored voice.
“What?” Nightmare Moon exclaimed, grumbling as she rubbed some of the magic dust that had clung to the sides of the jar to look out and see a bored dark alicorn chewing on a piece of fruit and idly flipping through a book, “Luna? How are we separate! We should be one again! Then we may combine our powers to truly defeat those loathsome ponies who wield the elements and let the night REIGN FOREVER!”
Luna ignored the voice of her inner darkness sitting inside the jar and flipped another page and reached for another piece of fruit. “Nah,” she said, chewing, “I like it this way better. Me enjoying a book while you stay in the little jar. Just as planned.”
“Planned? But… How did you even know I was going to return? There were no prophecies this time,” the toy sized Nightmare Moon shrieked, “I demand to know how this sorcery was done.”
“Discord broke out of his prison in the last year. We figured if he could break out it was possible you might show up again too. Celestia and Twilight helped me enchant the mason jar, just in case.”
“So now what do you plan to do with me,” the tiny alicorn replied haughtily, “I have as much power as you, this jar will not hold me for long.”
“I’m pretty sure you don’t actually. You were using my magic for everything last time and now you’ve barely got a body. By all means though do try. The elements won’t be here to zap you until the Celebration is over, and I’m sure Twilight will appreciate the extra data,” Luna waved a hoof negligently in the direction of a large machine that had wires leading up to the top of the jar, “I’m going to take a nap now. Later Nighty,” Luna lifted the glass and put it in a box, raising the lid to seal it in.
“You can’t do this! I am the Queen of the Night! I will rule all of Equestria! Strike me down as many times as you like I will always return.”
“And we’ll have the jar ready for you every time until you learn to behave yourself. Remind me to take you out for a while next time though. Ponies do a lot of new and interesting things at night these days. It will be fun,” Luna told the jarred pony.
“Fun?” Nightmare Moon asked, the word sounding foreign on her lips, “What is this f-“
“The old word for it is ‘spaß’, don’t worry I had to look it up too. Language kind of got ahead of us,” Luna answered the forming question. Her head looked up from the jar and a voice could be vaguely heard from inside the jar. “Coming!” Luna called out, turning back down to the jar, “You think about that. Night Nighty!” And then the hovering box lid came down and sealed a stunned Nightmare Moon into darkness. She stayed there until the next day when the box was blasted by the Elements of Harmony, and she was banished for another while.
Norse Pony’s comments: Heh, I love the cavalier attitude on display here, the “meh, Nightmare Moon, big deal” that’s going on. The teeny-tiny Nightmare Moon in a jar is a hilarious image, and I like the promise of redemption that you offer for her. Good stuff.