"Don't believe the Great and Powerful Trixie?" The showmare laughed theatrically. "Well then, I hereby challenge you, Ponyvillians. Anything you can do, I can do better. Any takers? Anyone? Hmm? Or is Trixie destined to be the greatest equine who has ever lived?"
With a grin, Twilight Sparkle teleported onto the stage.
Trixie blinked her eyes, shaking off the teleport's flash. "Oh please. Many unicorns can teleport! That is but a paltry task to the Great and Powerful Trixie!"
"Oh no, that wasn't my challenge." Twilight grinned even wider. "This is." Her horn glowed, and soon, so did Trixie.
Thick curls of magic wrapped around her. Long, wispy wings sprouted from her back. "What? What are you doing to Trixie? Stop this at once! You cannot possibly have the magical power to–" Trixie stopped when one of her legs shrank. "What?" In a moment, the rest of her shrank too, leaving only her cape and hat slowly floating down to the floor of the stage.
The spectators gasped.
Something under the hat wiggled. Slowly, it worked its way out under the brim, finally popping out from the side. A tiny Trixie-colored breezie stood and blinked in the sun, looking up at Twilight. It squeaked.
Twilight laughed. "Okay, can you match that?"
The breezie squeaked more, shaking a tiny hoof at Twilight.
"Oh don't worry. I'll change you back." Twilight looked down at Trixie and raised an eyebrow. "As soon as you admit I am the most powerful unicorn in Ponyville."
Trixie stood still for a moment, her mouth gaping. Her silence didn't last long. She exploded into a tirade of squeaks and shrieks. It was completely incomprehensible, but several mothers in the audience saw fit to cover their foals' ears nonetheless. Finally, the flood of babbling verbal abuse faded away.
Twilight still stood above Trixie, waiting.
Trixie looked down and away. She gave a tiny sigh. A few miniscule, barely perceptible squeaks followed.
"There." Twilight smiled, more genuinely this time. "Isn't that better?" She fired up her horn again, returning Trixie to her former unicorn self.
Trixie stood there on top of her hat and cloak, staring at Twilight intently and trembling... but she didn't dare to make a move. Eventually, without saying a word, she walked down from the stage, levitated her clothing after her, and disappeared into the back.