Twilight isn't having a very good day. An experimental spell blew up in her face, an army of changelings is attacking Canterlot, and she just died. Yet somehow, it looks like it's going to keep going downhill from here.

Given the chance to correct what's gone wrong, Twilight swears she's going to fix all this even if it kills her. Which it will. Frequently.

Cover art by Pixel Prism
Spanish Translation
Series TV Tropes page

This story is a sequel to A Stitch in Time

Having discovered the message left for her by Star Swirl the Bearded in the distant past, Twilight once again finds herself caught up in the middle of a struggle against forces far greater than herself. In order to even stand a chance she'll need to travel further and wider than she ever has, and forge some unlikely alliances with old enemies. All to bring down the powers that have manipulated and shaped her entire life, and retake control of her own future.

The conclusion of the Time Loop Trilogy, which began with Hard Reset
Available in Spanish thanks to dgs1993
Series TV Tropes page

This story is a sequel to Hard Reset

After the events of Hard Reset Twilight's life and mental well being are slowly returning to normal. Her recovery is cut short, though, when a letter arrives informing her that the time loop spell she cast is causing severe damage to space and time itself. In over her head, Twilight tries to summon anypony who will know how to fix it. The pony she gets is the last one she ever thought she would meet... and nothing like she expected him to be.

Available in Spanish thanks to dgs1993
Series TV Tropes page

This story is a sequel to Project: Sunflower

After the events of Project: Sunflower, Erin Olsen has returned to Ponyville, happy to pursue her studies in magic. After everything that happened the year before, she's looking forward to spending her days studying and having fun with her friends.

Meanwhile, on the newly discovered world of Harmony, humans and ponies work together to study this strange new world. However, their arrival causes something ancient to begin stirring. Something that may end up changing everything.

Erin will need all of her courage, all of her cleverness and, of course, all of her friends to see herself through what happens next.

Cover art by Valkyrie-Girl
Editing provided by:
Brilliant Point, Coandco, Ekevoo, Ludicrous Lycan, Merlos the Mad and Razalon the Lizardman.

It is the year 2038, and the Earth is slowly being consumed by a space-borne monstrosity dubbed the Black Tide, which is using nanotechnology to remake the planet into something hideously alien.

Erin Olsen works for Project Harmonics, humanity's last-ditch effort to find a new world before the Tide can wipe them out. But when that world is found, and it turns out to be occupied, Erin will need to find the courage to face the unknown in order to save the inhabitants of both worlds.

(Many thanks to Easteu for the fantastic cover image for this story!)

Now with its own TV Tropes page

There is now a follow-up to this story: Sunflower - Side Projects
Sequel: Project Sunflower: Harmony

This story is a sequel to Stardust

Times are changing for Equestria as Twilight’s return brings with it news of people and cultures from beyond the peaceful world everypony knows. Aid and volunteers are freely offered to help the besieged humans of Earth because every Equestrian knows that’s what good friends do. Unfortunately, making friends can also have the unintended consequence of making enemies.

When the monsters besieging the humans strike at Equestria with a level of brutality not seen in over a thousand years, the cry for help is sent to all the kingdoms of the world. Honored allies step forth to fulfill ancient treaties and oaths. Enemies, old and new, bury their grievances. An alliance never before seen in Equestria will be created to combat the monsters from the void.

And because of these events, a grim but welcome sibling to the XCOM project is born.

(XCOM/FiM Crossover)
(Sequel to Stardust, which I recommend reading before starting this. Fortitude Amicitia and Broken aren't required reading but are supplemental to the storyline)
(Gore tag for blood and violence)
(Alternate Universe tag because of the divergence from canon that Stardust has caused)
(Uses elements of Season 4)
(Coverart produced by the amazing Carnelian!)
(Many thanks to Arzoo, BradTheBrony, Vandenbz and Setokaiva for prereading!)
(As of 03/07/2016, the prereading team consists of Arzoo, BradTheBrony, Noble Cause and Metallusionsismagic!)
(Complete with it's own TVTropes page as part of the Stardust continuity. Could use some updating!)
(Character tags will be added as chapters are added!)
(Featured 5/12/2014! Thanks folks!)
(Possible spoilers in the comments! BEWARE!)

This story is a sequel to The Irony of Applejack

Warning: this story is a sequel. Therefore, it is highly recommended that you read the prequel first before continuing!

Over half a year has passed since the changeling attack on Ponyville, and Applejack would like to think things have finally settled down. Much has changed for the young changeling, and all of Equestria in kind. The new district in Ponyville proves that, along with the town's many new residents.
But there is much the young queen does not yet know about being a changeling. Some things, she will learn, can be chosen, while others will be chosen for her. With new allies and enemies emerging all around her, Applejack must discover what it truly means to rule before the choice is taken from her forever, and the history of the changelings repeats itself, once again...

Image provided by Heilos.

Isolated from her friends and taken prisoner in the middle of a war, Twilight must deal with the very real dangers of being percieved as an enemy as well as the nightmares of her arrival on 'Earth'. Can she overcome her own fears and the fears of her captors? Will the wayward unicorn's assistance be a boon or a curse to the 'humans?' Most importantly, will she ever find her way home?

"In short, it's a story of friendship and plasma rifles, with the emphasis on the friendship. The characters are well written, the XCOM setting is fleshed out very well, and the story is compelling. If you love XCOM, you'll love the story, but even if you've never heard of it, it's more than worth giving the first 3 chapters a read.

There's excellent action later on, but the real strength lies in the collision between the friendly and naive world of Twilight Sparkle and the desperate world of humans fighting a losing war for survival and willing to do anything to turn the tide."

--Arzoo

(XCOM/FiM crossover)
(Cover art commissioned by a friend and created by the magnificent FoxInShadow!)
(Original cover art by the amazing Carnelian can be viewed here!)
(Gore tag for blood and some violence)
(Many thanks to the studius OminousTen, Arzoo, xXFluttershyForeverXx and finally Setokaiva for giving my rambles a once-over)
(Now with it's own TV Tropes page! Get to tropin' folks!)

For most of Applejack's life, she didn't know what she was. True, she understood who she was well enough.
But ponies don't change shapes, nor do they get strength from love.
Applejack never thought too hard on it... until the events of a certain wedding brought about some harsh realizations.
Now, with Equestria still reeling from the surprise attack, will Applejack manage to come to terms with what she is? Will she even be able to keep her secret safe?
For if the royal guards don't get her first, the conspirators in the shadows just might...

Image provided by Heilos -

Rarity's exploits in "Sweet and Elite" set in motion a chain of events that will find the unicorn dressmaker taking part in the greatest airship race in the world, the Alicorn's Cup. Excitement will give way to terror, as Rarity soon finds herself the victim of a plot against Equestria, and shipwrecked far from home with her least favorite stallion, the boorish Prince Blueblood. Rarity will learn of treachery in Canterlot and abroad, and will have search for something of substance beneath the prince's obnoxious veneer as she struggles to not only save herself, but her entire nation.

Part One of Three
The Adamant Triskelion - Book One: The Flight of the Alicorn
The Adamant Triskelion - Book Two: The Abyssal Forge
The Adamant Triskelion - Book Three: ???