This story is a sequel to What Have You Done?

Chrysalis, the Changeling Queen, has taken her prize, unhindered by Equestria's precious heroes. Celestia is little more than another prisoner of war now. The Bearers of the Elements of Harmony are lost, and the Elements themselves have turned away from Equestria's plight. As the world they once knew begins to crumble, a single question is asked among the people as they look up at their fallen heroes.

There is no such thing as "miserably ever after," for someone will always be fighting for things to change. Hope doesn't die just because someone's turned off the lights. Truth doesn't vanish when deceit begins its reign, and Harmony can only shine brighter among chaos.
Even as this world falls, we'll work to build it up again.
Even as you lose yourself, you can find greater things within you.
Even as fear rises up like a tidal wave, we'll forge a sanctuary to stand against it.
Even as you break, someone will always be standing there next to you to carry you through it.

Cover art is by Odin-odin.
Story theme (Equestria in Grey) is by Omnipony.
Main Characters are Twilight, Velvet, Discord, Nightlight, Luna, and Chrysalis, in that order.
See you in the comments, my dear readers.

Twilight has been having her study sessions with the Cutie Mark Crusaders for some time, and has been remarkably pleased with their progress. And kind of worried, as they keep getting better and better. She might be a princess now, but TEACHING THE CUTIE MARK CRUSADERS? She'd rather not become their formal mentor. Yet.

A letter is sent out, and Princess Celestia gets a call for help. And, an opportunity is born. After all, why not? After a thousand years, perhaps it is time to do something else, just for a bit. She does have a rather wonderful younger sister who hasn't been ruling a land for a thousand years, and who has been studying how to rule for the past four rather intensely. So, teaching three fillies undercover? Sounds like fun.

And Luna. She's wanted to be as respected as her sister so much that she once went mad over it. But now, she's simply being handed the power that she once coveted for so long and no longer wants. What kind of a world does she live in now that her highest desire has been so casually granted?

With all of this, What Could Possibly Go Wrong?

Arcs:

Escape: When Celestia hears the call, she jumps at the chance to teach again, especially three fillies who might surpass her grandest student. But first she's got to escape her own identity...
Examination: So you want to find out what a filly does? Time to test her silly, so long as you don't taunt the Happy-Fun Filly.
Excitement: So, you've found the Happy-Fun Filly. Great, but the other two need help as well, and Scootaloo has this ~Great!~ idea for how to use her new-found magic...
Encouragement: Cometh the Bubbles, and a whole load of new headaches as they find out just what being a Happy-Fun Filly really means...
Exaltation: Where's Luna been this whole time? She can't be very happy about being left in the lurch holding Equestria. She could really use somepony to talk to.
Exercise: 'Sunbeam' is looking to teach the Happy-Fun Filly more, but first she needs to start taking care of the wagon-tire she keeps around her middle so that certain Unfun-Time Fillies don't interrupt her. And there's this big draft stallion looking for help...

This story is a sequel to Celestia's Tiny Student

(Title changed from "Ponyville's Tiny Librarian" for reason pointed in this blog )

Twilight Sparkle is a one-kilogram pony the size of a large rat, shrunken by Princess Celestia following her entrance exam to the Celestia’s School for Gifted Unicorns to ensure that her power surges would not pose a danger to the ponies around her.

She’s spent thirteen years full of hard training at her new size, facing the life-threatening experiences that came with living in a world of giants. To survive those thirteen years of hardship and joy, of learning and adventure, and of pride and humility, Twilight has challenged herself to be stronger, to overcome any obstacle.

Now that tiny Twilight is on her way to Ponyville to oversee the preparations for the Summer Sun Celebration, how well will this miniature mare fare outside of the confines of the castle? How will the other Element Bearers react to her? How will Nightmare Moon react to the tiny unicorn? Is Twiny prepared to face Ponyville, and, more importantly, is Ponyville prepared to face her?

Credits:
Art cover - kc day

Top editors: (editing and rewritting for months, hope quality is to your liking).
Kydois
Georg

Nightmare Moon's sentences editor:
Bahatumay

Applejack accent editor:
Crimson Star (Chapter 1 - Applejack)
Rebel Brony
The Notebook is grounded

Pinkie sentence's editor:
Plump it UP

Other editors:
Hereward
tana1100
Lab (small editing from prologue to chapter 4)

Pre-reader:
Rated Ponystar

To celebrate the release of this sequel, I created a group called “Twinyverse” for all fans of this story where you can talk about it and track all side stories with ease.
The Twinyverse Group

This story is a sequel to The Golden Armor

It's more of a continuation than a sequel, but whatever.

Comet is the leader of Princess Celestia's personal guard. Angel is the leader of Princess Luna's.

Comet is awake during the day. Angel stays up all night.

Comet likes using a halberd. Angel excels at using claws.

Comet is a pegasus. Angel is a bat pony.

Together, they take on all the twists and turns life hands them. However, things don't always go as planned.

Cover art by Equestria Prevails.
Proofread by jmartkdr and Feather Scratch

The past always comes back to haunt the present, there is no escaping the inevitable. For decades, Celestia has kept a secret from her student. A secret she made out of pain, and through pain will be revealed for all to see; for Twilight Sparkle is the secret daughter of the Sun.

Now, there will be consequences.

Consequences, they come in all shapes and sizes for every decision. For every action there is an equal and opposite reaction. These words are lessons that Princess Celestia should know, bits of wisdom she practices in her rule of Equestria. How is it then, that when faced with a decision, she chooses the one that would inevitably bring the most pain? How is it that she couldn’t bear being recognized as the mother of her child? And why? Twilight Sparkle is about to find out.

Disclaimer: (I do not own the picture; Title Picture owned and designed by KitsuneHino; Source: http://mel-rosey.deviantart.com/art/By-my-side-364777307) (I do not own any of the characters, places, events, etc. outlined in this fanfiction, MLP FiM does under Hasbro, give them the credit.)

Twilight Sparkle was presumed to be dead. Destroyed without even a body to bury, the young victim of a deadly magical surge that claimed the lives of many others along side her. More than a decade later, reports of a violent murder by a pony bearing her name are brought to Celestia and Luna's attention. A trail of carnage leading directly towards Canterlot's doorstep, brought by a pony who strikes without mercy. As Twilight approaches, in service to an unknown master, the Alicorn Sisters desperately try to uncover what happened all those years ago.

Edited by Zintegy and The Pink Mugsy

Chapter Heading Art by KirillK
All Sketches and Artworks can be found HERE

Talks broke down. The unification failed. Hearth's Warming have never occurred. The Great Pony War divided the land, and fears of a prophecy forced the unicorns deep underground and into near extinction.

Almost one thousand years have passed. The curious unicorn Sparkle yearns to breach the surface to discover its many wonders and to search for her missing father and brother, both of whom crossed over many years ago. She is forbidden to leave the safety of her subterranean village of Unicornia until she discovers an orange earth pony washed up on the shores of an underground river. That pony bears one of the six Elements fabled to change the world.

Or destroy it.

Cover art credit goes to ouyrof.

Re:Harmony was conceived before Season 4 aired, so some personalities and character relations do not line up with the show's canon.

Also, please refrain from revealing spoilers in the comments. Thanks!

Princess. Alicorn. The pillar of all ponykind, against which so many ponies often judged themselves. Celestia hates having to constantly be these things, and it's past time for a break. Luna will watch over Equestria while her sister is gone, but taking a break from your duties and taking a break from how the world sees you are two very different matters. Enter Prominence, a quiet pony who nopony really pays much mind to. Perhaps because she doesn't exist.

Aided by this disguise, Celestia will find her peace and relaxation in the home of one of the few ponies who know Prominence's true identity: Princess Twilight Sparkle. But when Twilight begins to see Celestia as a pony, and not a princess, can she deal with the feelings that arise? And are the feelings for Celestia, or for a pony she knows is not actually real?

EDIT: I've been featured, July 19th, 2014. I have no words to express how terrified and humbled and terrified and proud and happy and terrified this makes me.

Twilight Sparkle has too much magic, and it will take her decades to learn to control it. Her spectacular loss of control during her entrance exam only proves that fact. She is a danger to herself and others.

After Sunset Shimmer’s disappearance, Princess Celestia needs a new student to bear The Element of Magic to defeat Nightmare Moon. With all of Equestria at stake, Twilight Sparkle…is not the pony she needs.

Princess Celestia seals Twilight Sparkle’s magic with the distant promise of one day teaching her.

But there are two diarchs of Equestria. Amidst a lucid dream, an offer is made.

“Hello, Twilight. Would you like to be my student?”

Cover art provided by Lafiir.