Celestia has finally left this world, and Twilight has to step up to her place as Princess beside Luna, becoming Regent of the Sun. She has to learn what being a Princess entails, and live up to Equestria's standards.

Two Arcs. (More arcs will be in Sequels)
Arc 1-Chapters 1-6
(7 is a Bonus, all about the laws of Equestria. It will be updated irregularly.)
Arc 2-Chapters 8, 10-? (9 is a Bonus about magic, and will be updated irregularly)

Note: bonus chapters are not necessary for the storyline, but help comprehension.

The battle from Chapter 5 is in a separate story, Maripony Massacre

I now have a Beta-Reader, Arc 2 Chapter 2 -Arc 2 Chapter 6. Thanks to imperfectPacifist!

I have an editor, Arc 2 Chapter 7. Thanks to Commander Fire Starter

Credits for OCs:
Alexandria (by Elric of Melnipony) Alexandria's info here, first post

What if Spike had been home when Tirek destroyed the Golden Oaks Library, and had been killed? What would Twilight do? More importantly, who would be able to stand in her way and stop her when she delivers retribution to those who have caused her to lose everything? After she defeats Tirek in combat, she turns her focus on all of Equestria, and those whom she lays blame upon for the death of one she held dear to her.

With the combined powers of all the princesses inside of her, and a deep anger within her soul, can she be stopped, or will all of Equestria answer to her wrath?

Written for the Twirant's Kingdom Competition in the Tyrant Sparkle group.

Proofreading and editing done by:
DustyPwny

It's been two and a half years since Twilight Sparkle returned from the other world, leaving Sunset Shimmer in the company of the alternate group of friends she made. However, not all has gone well for her one-time rival in the other world. On the night of the 30th moon, Sunset emerges from the mirror and uses an ancient relic to switch their bodies. Alone in the care of Sunset's overbearing ex-tutor, Twilight uncovers the forgotten past that drove her rival to such desperation, while back in Ponyville, Sunset struggles with Twilight's lifestyle clashing with her own dreams.

Proofreaders: RTStephens, Winter Solstice, The Albinocorn, Dartrunner and NightWolf289.
Cover art: FallingRain22

Featured by Twilight's Library September 2014.
Featured on Equestria Daily

In the aftermath of her battle against Tirek, Twilight Sparkle is unwell. She wants more. She needs more. And she is afraid of what others might think of her.

But even in the midst of her growing despair that she has betrayed everything she stood for, she learns something about friendship and what it means to be an alicorn.

After the defeat of Tirek, Equestria is safe once more, but Luna can sense that her sister is troubled. When Celestia retreats to the starry realm of ascension in order to look upon the past, Luna joins her to discover what is bothering her.

There is now a Spanish translation of this story, courtesy of Spaniard Kiwi

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 wakes up, strapped to a hospital bed with a nasty enchantment that begs the question, why do they want to keep her here so badly? Stuck in a dream for two days, and with a little filling in from her friends, she learns that not only she has amnesia, she perhaps committed some very terrible crimes to pony kind. The mystery only gets deeper from there as conspiracy theories, tragic lifes and the severity of Twilight's madness gets uncovered.
Needless to say, she breaks free.
(This story takes place right after/in between Lesson Zero.)

Celestia fails to save Equestria after Nightmare Moon's encounter. Ever since then, Celestia was nowhere to be seen. A thousand years has passed. A pony named Twilight Sparkle, a captain of the royal knights finds a book about the elements of harmony and the 2 princesses who ruled this land together. She chooses to find where Princess Celestia has disappeared to and save the corrupted princess.

((Twilight is not an alicorn here, she does not have wings.)

The Mane Seven are on a mission to spread friendship across Equestria. It sounds easy enough, but should they let their guard down?

Twilight is confident that she can cope with any situation. Maybe she’s right and there really is nothing to worry about... Maybe.

[You may also revel in the Youtube reading (Chapter 1, Chapter 2) or mp3 download (Chapter 1, Chapter 2) that are available for this story.]

This story has it's own TvTropes page.

It was approved by:
Goodfic Bin
Black-light's Library!
Fimfiction’s Addicts

Here's what the readers are saying about it:

Dude whoa.... That was powerful. It kinda reminds me of “If you love something” let it go. The type of pony that Twilight is I could imagine that losing her friends would make her go insane, and I know she'd do anything to still be with them. Great story. Mad I didn't hear about it until now. ~ Man on the Moon

Princess of Friendship by Bad Dragon is a great piece of work. ~ Stinium_Ruide

If Twilight can't find a way to save her friends, she'll make a way. And that works out about as well as one would think. ~ FanOfMostEverything

I hope Twilight can let go... eventually. ~ StormyVenture

I liked this story. It was heartbreaking, a bit confusing (in a good way), and overall enjoyable. ~ Heart Felt

it had the nerve to make me experience something you twats call “the feels,” but a nice enthusiastic walk in the woods solved that problem. ~ DR_LaZer

made me cry… ~ deli73

I cried. I didn't shed one tear, but a thousand. ~ Crystal_Chaos

Great story, definitely deserves the tragedy tag. ~ MustacheMerlin

This story really does earn it's tag as it presents a situation that cannot be won and that has no positive outcome, which is part of tragedy in it's strictest sense. ~ HapHazred

Brilliant. Both her plan and the story. ~ Unbridled Dolly

I love it when a story comes together--and I say that this one did, at least for philosophical egghead dorks. ~ Mahayro

I love the entire premise and the ending was perfect. ~ Curify - ChasingVerse

Twilight sparkles wakes up to some bad news.
Apparently she went crazy with magic and decided to try to take over the world, including Equestria.
Oddly enough, this has been working out rather well.
Unfortunately for her she seems to of forgotten most of it.
Goodluck Twilight!
[New chapters being edited. Old chapters being edited as time allows.]