SF (canon species only; no humans) Ponies were magically and genetically engineered to be the perfect servitor race. They are powerful, adaptable, intelligent and completely under the control of their creators. A laboratory accident frees one such pony from her mental chains, but how can one mare save herself and the rest of her kind if she doesn't even know she's a slave?
This is not the Equestria you know and these are not your little ponies... not yet, anyway.

Tags: Adventure, Diamond Dogs, Gryphons, NO HUMANS (did I mention that already?)
Other tags: historical, mind control, Clarke's 3rd Law, excessive use of high energy physics, before they were famous.
Detailed review by PaulAsaran.
Cover art by endrome , used with permission.
Russian translation (partial -- 'unofficially' completed in the comments)
A Soot-Covered World, book 1.

Twilight Sparkle just can't find enough time in the day. She has to study friendship for the Princess, hang out with her five friends, and juggle her own hobbies and interests besides. But when a novel solution presents itself in the form of an experimental new spell, will it solve her time crunch, or will she be distracted even further?

After the changelings' failed invasion of Canterlot, Twilight tries to soothe some of Ponyville's rampant paranoia by casting a spell to prove there are no imposters hiding in the town. But her spell leaves her in an alien body, facing a mob of angry ponies who just don't believe her when she says she is Twilight Sparkle.

Or, at least, she was Twilight Sparkle, anyway...

Featured on Equestria Daily, 2/17/13
Cover art is by the awesome and amazing Conicer

On a dark night filled with even darker magics, an insane cult attempts to give Nightmare Moon a body and life of her own, utterly separate from Princess Luna. But, when the spell is interrupted by Celestia, something unexpected is created.

Now, a little black alicorn filly named Nyx finds herself living under the care of Twilight Sparkle, only to be haunted by memories and emotions from her past. Is she Nightmare Moon reborn or is she simply a doppelganger with a soul and mind of her own? Can Twilight Sparkle protect Nyx from those who refuse to see past her dragon eyes and black coat?

Or, will Nyx be forced to inherit the sins that may not even be hers and become the greatest evil Equestria has ever known?

When Rainbow Dash suddenly proclaims her love and adoration for a certain 'Miss Sparkle' and tells her friends the story of how the unicorn 'fixed' her, the girls are hesitant to take the situation at face value. However, even they can't deny it when the facts begin to build into a case against Twilight. Twilight claims innocence but her words sound like hollow excuses and obvious lies. The four of them are left wondering if Twilight Sparkle is truly the hero she once was or if she has finally allowed her true nature to show: the nature of a heartless psychopath.

[ Spoilers in the comments... So many spoilers... ]

[ 'Miss Sparkle' occurs a few months before Twilight's ascension, early in the spring of Twilight's second year in Ponyville. According to my version of the chronological timeline, the only episodes of the first three seasons that have yet to take place are (in chronological order) "Wonderbolts Academy", "Just for Sidekicks", "Games Ponies Play", "Spike At Your Service", "Keep Calm and Flutter On" and "Magical Mystery Cure". ]

[ The cover art was made by the oh-so-generous tehmisiu. Thanks again! ]

[ 'Miss Sparkle' placed first in (Incoming spoiler of story-ruining proportions!) Blundy's TwiDash Framed Challenge! Thank you all so much for your support! ]

[ To top it off, Twilight's Library found it worthy of being added to their shelves. I'm at a loss for words as I write this, and I probably will be when you read this too. Just... Thank you. Thank you all so much. ]
[img]http://i.imgur.com/m9vLrr7.png[/img]

Ponyville is being utterly obliterated by Twilight Sparkle, or at least somepony who looks exactly like her. She wakes one morning to the devastating sight, somehow having lost her voice and her ability to use any magic. With no way to convince any one that it's not her causing the destruction, she is callously sent away by her impostor to face her doom. Suffering through immense turmoil and emotional pain, will she finally find her ultimate savior not within herself, but within Rainbow Dash?

What will become of Twilight and Ponyville? Will the impostor Twilight stop only at Ponyville, or continue to go for a much greater target? And are the impostor's motives really as sinister as they appear to be?

--This is my contest Entry for Blundy's TwiDash Framed Challenge-- Completed.

Many thanks to a thorough and helpful contributor--> Senyu
Thanks also to my helpful prereader/proofreader/editor--> LightningBass94

After Rainbow Dash loses a wing in an accident Twilight finds herself to be the only pony capable of restoring it. But can she reconcile the month long treatment with her suppressed feelings for the pegasus?

I wanted to change a lot in this story before submitting it here, but then it took longer than expected and I had other things to take care of. So, after only the most basic revisions, here it is in all its imperfect glory. And in chapter form, too.

Cover image by me.

Skipsy also made a comic for it.

When Twilight discovers an invisibility spell, she decides to use it for pranking her friends. However, she soon finds out some interesting news that one of her good friends, Rainbow Dash, might be interested in her as more than friends. But can Twilight accept this news, or will she rebuke the rainbow maned mare? What chain of events will this set off?

Edited by The Abyss

My amazing cover art was drawn by Graphic~Lee!

An extensive re-edit will be happening soon. Expect a re-working of the ending, if it stays the same.

A lot happened to Twilight Sparkle the year before she made the transition to Ponyville, before she realized the value of a friend, and before she saved all of Equestria...

After a chance encounter with "Rainbow:" an enigmatic, amnesiac pegasus mare with a rainbow-striped mane and a knack for mischief, Twilight begrudgingly finds herself overseeing her recovery, all while questions keep surfacing. Like who is she? Where did she come from? And more importantly... why can't she get her off of her mind?

As days turn to weeks, and weeks turn to months, destinies are revealed and the past is dug up as Rainbow's memories begin to resurface; and as sinister forces set their sights on Equestria, Twilight and Rainbow find they must overcome themselves in order to become the heroes they are meant to be.

Edits for the story provided by xgfhj.

Sequel officially now in progress exclusively (for the time being anyway) over on my patreon.
Check out the sneak preview here.