This story is a sequel to Princess Celestia The Changeling Queen: Stories Behind the Mask

At the Royal Wedding, Chrysalis and the Changelings were revealed to all of Equestria.

But another mask was torn away that day. A mask born for a thousand years. A mask created on one promise. A mask, that has become synonymous, fused, to its bearer.

A mask that when ripped off, causes Twilight, her friends and Luna to question everything they ever knew about the one pony, one very important pony.

At the Royal Wedding, the meaning of the phrase 'Princess Celestia' changes forever.

NOTE: Chrysalis is NOT Celestia!!! That'd be impossible to pull off.

Credits to: Plainoasis for the design of the cover art
Note 2: Original cover art here: https://angelea-phoenix.deviantart.com/art/Contest-entry-Changeling-Celestia-337023552

Pre-read/edited by Zervziel,
Blankscape,
FinalFan,
Courage Fire
Aurora Borealis

Side Stories to this can be found: here.

An audio-reading on youtube up to Chapter 21 is up by StraightToThePoint Studios. I'm aware there are others but this is the nearest complete one: [embed]https://youtu.be/X3eMW673CSY[/embed]

There are also 2 print versions of Princess Celestia:The Changeling Queen. Nonexistent Publications run and Ministry of Image's run.

Contribute to the TV Tropes Page (thanks to Babs_Seed72 for getting it up)

A damaged robot pony, unlike anything ever seen in pre-industrial Equestria, is found in the orchard. Before it collapses, it says only two words: "Twilight Sparkle..."

Twilight fixes the mechanical mare and gives her a new directive: "Make friends." Now a robot must learn what it takes to be a good friend and, while she's at it, what it means to live...

Featured on Equestria Daily (11/22/15) and The Goodfic Bin! (3/20/16)!
Featuring illustrations by Colby Green (Illustration Gallery found HERE.)
Editors: GaPJaxie,The Knight Templar, GenerousGhibli, E3gner, and Reese.
Technical Consultants: Artichoke Lust and JFalk.

Now with its own TV Tropes page!

Princess Twilight Sparkle discovers a centuries-old mystery hidden in the Royal Archives. Her investigation leads through layer after layer of deception and misdirection, setting her hooves on a path that seems to be leading to a mysterious secret. Along the way, she learns that some friendships can be very, very strange.

Book 1 of the Alicorn Adventure series.

AUDIOBOOK by VisualPony
Featured at the Royal Canterlot Library
TV Tropes Page (Courtesy of Sandtalon)
Goodreads Page (Courtesy of Facedeer)
Equestria Daily Page

WARNING: Major spoilers in the comments. Takes place several months after the end of season four. (Not a Da Vinci Code crossover, BTW!)

Do you see a dark tag? No, you don't. Not dark. Well, okay, there are a couple of dark-ish bits, but that's all. Not enough to warrant a tag. Speaking of tags, there really ought to be "Badass Twilight" and "Friendshipping" ones.

Sequels and side-stories (and more) can be found here Offprint and AO3, and a hardbound two-volume set of all that can be ordered from The Ministry of Image.

My editor for the first edition of this story was Gogito, and I can't thank him enough for all the hard work he did. My editor for the revised version was PresentPerfect, and he did a terrific job of getting the story into excellent shape.

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

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?