Twilight was silent… as all mares generally would have been in her situation.
"Oh enough with the silent treatment!" Her reflection snapped back through the glass. "Already do I feel like it's getting old."
Twilight could not help but faintly laugh in response.
"Oh there we go, there we go!" Her reflection went. "That is progress. Progress is that!"
"You sound funny." Twilight observed.
That was true enough. Her reflection, though she knew its real identity, had a very distinct snarl, hovering somewhere between masculine and feminine. It would have sounded threatening, but all indications of that were completely lost due to the fact that it was coming out of her mouth. Maybe another pony may have felt intimidated, but Twilight was her own being, and she was hardly about to be bullied by her own reflection.
"Alright you." She said, before the mare in the mirror could get another word out. "I'm ready. Do your worst."
"Ah!" The Twilight said before her. "Straight to the point, I love that. Though it may simply be due to me being completely and utterly infatuated with everything about you. So perhaps I might have the bias opinion here. But I digress…"
"Quit stalling you." The real Twilight snapped impatiently. "What do you want?"
"Well now, that's a really good question." Her reflection continued. "What exactly am I allowed, hmm?"
"What are you on about?" Twilight said, her head starting to spin from all this fast paced talk.
"Oh, nothing in particular." Her aspect expressed. "I just thought I pay a little visit to a very special mare. Did you know that the population of Canterlot is exactly three quarter's unicorn and one quarter everything else. I find that pretty interesting, don't you?"
"Oh for the love of…" Twilight exclaimed. "Stop talking nonsense!"
"Well that's a fine how do you do, isn't it?" The mirror mare replied offended. "Why it's almost enough for me to hop right out of this mirror and give you a good talking to. In fact, I might just do that…"
Twilight stepped back, for her visage that now looked back at her was growing ever so closer. And to her surprise, the unicorn that mimicked her did indeed trot right on out of the mirror, stopping right in front of her and eyeing her with an undiscernible look.
"Ah, ain't that just so much better?" She mused. "Much more personal this way."
Twilight observed her copy standing tall and proud in front of her. She was indeed the spitting image of her, like she really was pulled straight out of a mirror. That is, except for one particular aspect as she looked down.
"Ah!" Twilight exclaimed in shock. "Your hooves!"
"What about my hooves." The duplicate went. "They're really your hooves, aren't they… oh, wait a sec."
Both mares were now looking down to the copy's hooves. There were no mistaking them, for they were not in fact the spitting image of the real Twilight's.
"They're… cloven." Twilight managed to cry out, halfway between fright and disgust. "You got… cloven hooves!"
"That I do." Her copy mused, as if laying eyes upon them for the first time. "Odd that. I could have sworn I got this whole shapeshifting thing down to a tee. Let's see if I can't remedy this little hiccup."
She scrunched up her eyes, deep in thought. A whirl of magic swirled all about her, aiming directly at her imperfect hooves, split down the middle. Yet after the impressive array of magic had subsided, still the cloven hooves remained, looking only more out of place.
"Well now." The copy commented. "Ain't that just the most perplexing thing."
"What are you?" Twilight hushed in a fearful tone.
"Oh, now we're asking what am I, huh!" Her copy barked back, losing the aloft tone for one of disgust. "I think you of all conceivable creatures could comprehend what I am… Mother."
Twilight was silent, like somepony had cast a spell rendering her unable to emote in response to what she had heard. Her duplicate was having none of it, however.
"Again, with the silent treatment!" She exclaimed. "You know, I like you. But if continue to stand there looking all dumb in response to a simple little word, why… that I cannot abide!"
"What did you call me?" Twilight said at last, seemingly heedless of her copy's apparent wrath.
"Oh don't you get all warm and naïve on me, little lady!" The cloven unicorn barked back. "You know full well what I called you. Don't you act like its some big revelation to you?"
"Mother… me." Twilight uttered softly. "I can't be your mother."
"ENOUGH!" The copy bellowed, causing her to shake and cower in fright.
The imperfect stood tall and gaunt above her cowering first. She was fuming profusely, steam issuing forth from her snout and ears. Then, to the real Twilight's horror, she started to grow in size, the room stretching and darkening as the copy rose in stature, until her grotesque cloven hooves were just as tall as Twilight.
"You have confused, exasperated and diminished me to such an extent…" She stated. "That I have forgotten the initial reason I came here for. I hope your happy, Progenitor. Right now, I feel like vanishing to the four winds and finding some unsuspecting young mare's psyche to twist and fondle into new and crude shapes. Farewell, you cretin… You have not heard the last of me!"
And in an instant, the mighty Twilight dissolved completely into thick clouds of smoke. The room creaked, light coming back into it, as the blinding mists soon cleared, revealing the whole place empty, devoid of any life, save for Twilight at its center. Rising to her hooves yet again, she took a deep breath, trying to come to terms with what she had just witnessed, before the appropriate words soon manifested themselves and rolled off her tongue.
"Well that escalated quickly!" She expressed with a tone of immense bewilderment.