King Sombra’s dark influence was obliterated by the Crystal Heart, and the villain is well and truly dead. But when he attempts to steal the afterlife of an innocent victim, a human spirit is left hurtling towards Equestria, where this unfortunate soul is revived into the only vessel available: the reconstituted body of King Sombra himself.

Thus, a cheerfully oblivious alien is crammed into the form of the most evil and malicious being Equestria has ever known. Not that Shining Armor and Cadence know this, of course. As far as they are concerned, the King is back and he’s lost his fricking mind.

Click here for the TV Tropes page!

Brought to you by Loyal2Luna, this new Downloadable Content for Mass Effect 2 brings the fight to Equestria.

Just about ready to embark on their mission to stop the Collectors from further abducting human colonies, Commander Shepard and the crew of the Normandy SR-2 are given a new priority, when the Illusive Man tasks them with investigating the mysterious disappearance of a Cerberus science team.

Soon, what begins as a simple search-and-rescue unveils a mystery millions of years in the making, and the Commander finds himself thrust into a situation he couldn't possibly have prepared himself for.

Join the Hero of the Citadel as he uncovers the secrets, combats the demons, and ultimately decides the fate of the impossible world known as "Equestria."

Now Featured on Equestria Daily!
TV Tropes and a group of its own.
Audio version
( EPUB / MOBI )
Three Nights in Manehattan, a sequel
Hardcover Print-on-Demand Order Page

As a child, Daphne knew of a world where magic lived, where an immortal princess reigned over a beautiful kingdom, and longed to journey there beside Leit Motif, the filly she'd grown to love in the woods behind her home. But one day, when she needed her most, Leit Motif was gone, and she never came back to show her the way. As she grew, she put aside her childish dreams, and taught herself to believe the lie.
When forces beyond her knowing take her sister Amelia, though, she discovers that her childhood fancies were entirely too real, and is thrust into a journey that will take her back to that land she longed for, back to the childhood friend she'd abandoned, and to worlds she'd only dreamed of.

Interview with Pre-Reader Amacita
PresentPerfect's Review

This story is a sequel to Celestia Sleeps In

After the accidental discovery of humans, Celestia tasked Lyra with learning about Dale's culture and Dale's language. Two meetings later, a misunderstanding caused Dale and a Coast Guard woman to be inadvertently transported to Equestria. With the two humans hospitalized and communication limited at best, the Equestrians just want to heal them, while back on earth the Coast Guard wants nothing more than to determine what happened to one of their sailors.

This story is a sequel to The Monster in the Twilight

Now that Luna has returned to the throne, and the aftermath of her brief appearance as Nightmare Moon is being cleaned up, the story is over. Right?

Not quite.

Twilight Sparkle had nearly been destroyed in the chaos of Nightmare Moon’s return, but now with the assistance of her five friends, she is facing a fascinating new world filled with wonderful things. No longer the scarred monster who nearly destroyed Canterlot and raged through the Everfree Forest for over a decade, now she has been healed by the Elements of Harmony and is living at the edge of town with her adoptive mother Zecora. Not all the fears of her past can be left behind that easily though, and now she must face the consequences of her actions as she faces the most daunting challenge of her life.

Ponyville.

Letters is a sequel to the alternate universe story The Monster in the Twilight. In this story, Twilight Sparkle exchanges letters with Princess Luna, two ponies with a common problem of fitting in and making friends after the destruction of Nightmare Moon.

Normally I would try to talk you into reading the sequel even if you haven’t read the original story, but in this case, you’ll probably be more confused than entertained. But go ahead. I don’t mind if you don’t read the first story. You’ll never find out what an Urlock is, but that’s fine. It’s your funeral.

Editing Assistance by Alicorn Priest, Peter and Tek

Credit for the incredible picture All Night Study Group goes to Bibliodragon at Deviantart

Physical books are available on Lulu.com (up to Chapter 82)
Letters From a Little Princess Monster (Paperback) 726 pages
Letters From a Little Princess Monster (Massive Hardback) 780 pages

Reader, in ancient days, the old lords of the world numbered in thousands. Then hundreds. Then even less.
Now, they are found only in tapestries and fanciful ballads.
The creatures are all vanished. All but one.

Rumors say there are more of him, somewhere far away. A young and supposedly gifted mage called Star Swirl, and Heartstrings, a gentle spinster, have joined him on a journey to find the rest.

Featured in The Royal Guard's Fic Spotlight #5
TV Tropes page (that could use more love)

This story is a sequel to Steel Solstice

Continued in: My Little Apprentice: Apogee

Twilight Sparkle learns that the trust and goodwill of the Princess isn't always a good thing as she's given the trust of an important assignment. When that assignment turns out to be long-term, how will she handle taking care of a filly of her own? How will she handle this strange new filly, who proves to be much more than she appears. As a matter of fact, she seems to be from an entirely separate universe.

Meanwhile, Second Chance has kept only enough of her memories to know that she isn't what she should be. The wonderful world of Equestria has its own dangers, and she seems to have a knack for attracting trouble. The more of her memories return, the more she wishes she could just forget. But you can't forget when all of Equestria depends on you remembering.

Only one thing's for sure: The longer Twilight keeps this strange filly in her care, the stranger her own life will become, and things she thought she knew about Equestria will unravel before her eyes. Strange ancient devices, an eccentric mint unicorn and her so-called "Equestrian Precursor Society" are only the beginning for Twilight Sparkle as she begins a journey of her own. She too may wish she could simply forget. Unfortunately, it's too late for either of them.

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!)

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!)