Twilight Sparkle broke time when she got her cutie mark. Now Twilight and Sparkle are sisters from another time. Twilight is hailed as the potentially greatest light magician of all time, and already has a reputation as a hero by the time she goes to Ponyville. This isn't her story, not primarily.

Sparkle is an orphan - her dark magic killed her parents. She lives with her brother in Canterlot's industrial sector because they can't afford anything better. She can't leave either. She's a natural dark mage; while Sparkle won't go mad like Sombra, her reputation is hardly any better. Worse, the law doesn't see her as a good pony.

The fact that the dead don't stay dead around her, or that Thorn - Spike's double - is an undead, soul-eating abomination, are other matters altogether.

(Also has some Slice-of-Life, but fimfiction tags won't let me put it with Adventure.)

Has an ask blog to go with it: Ask Sparkle and Thorn.
Also has a TvTropes page: Split Second Tropes.

Featured on EQD.

Cover art by Swirling Line.

This story is a sequel to Split Second

Twelve years ago, she broke time. Two alternate timelines exist, each with a different version of Twilight Sparkle. Both versions of her are able to see the other. In this timeline, Sparkle is a Necromancer.

Or rather, she was. Sparkle is dead now, not that she cares. She's got a new body. With Thorn (her undead dragon son) and Cobalt (her apprentice and an assassin for hire) at her side, she's ready to take on the world. Again.

(Spoilers in the comments. Read at your own risk.)

Featured on EQD.
The Tv Tropes page
The Ask Blog

This story is a sequel to Split Second and won't make sense without it.
This story also loosely shares continuity with Lupine Tree. Reading that is not required.

Cover art by Swirling Line.

We trained her.
We taught her.
We raised her to godhood.
She brought us down to earth.

Sequel can be found here: Memoirs in Ink and Blood

Twilight Sparkle has obtained the combined power of all four princesses of Equestria. Wielding this power, she confronts Lord Tirek, but the result of their fight is a tie. When he holds her friends hostage, she is forced to make a difficult choice.

All is not lost, however: one force remains in Equestria that could give her the edge she needs to defeat her foe, save her friends, and restore the world. She need only retrieve it from Zecora and place it around her neck...

Runner-up (one-shots category) in the Twyrant's Kingdom Competition.

Story inspiration: Corruption of a Desperate Mare, by Chris Wöhrer.

Edited by NightWolf289, AugieDog, and Prak. Thanks also to Pascoite for his WRITE review.

Rated teen for gore and dark themes.

Featured on:
Fimfiction.net Feature Box (05/12/14)
Equestria Daily!
The Royal Guard's Fic Spotlight #10.

This story is 100% approved by Twilight's Library!
Approved by Nonpareil Fiction!

This story is a sequel to Lost into Shadow

Twilight has failed, or rather, she has succeeded. Her darkness is her power, and together with her husband, Queen Twilight has a new plan for all of Equis. The black castle rises to greater power than has ever been seen before. War is brewing while alliances are forged and others are broken. The days of harmony are dead and gone, and all the world will be forced to mobilize against the might of the Nightmare Hordes. Will they prevail in the faces of Wrath and Despair? Do they have any hope of someday returning to a time of peace and love?
....
........
Not a chance, because in Chapter 1, Hope dies.

Twilight had reached her peak, she was at the happiest point in her young life. The day of her coronation as Equestria's newest princess had finally arrived. Then the unthinkable happened, Sombra appears in the throne room alive and well demanding his chance to be reformed by pony society. The unthinkable happens again, when his wish is granted, spearheaded by none other than Princess Twilight herself. Will Sombra's nefarious plans bring her to ruin, or will she succeed against all odds? Only time can tell as it reminds them both that plans have a way of changing all on their own.

A normal day was all it took.
A simple failed prototype, a missed experiment.
There was an explosion, and I woke up. I don't really know what happened between those two events, but I'm fairly certain I shouldn't have awoken in a small, dark box.

I'm scared.

Cover art by the amazing Avatar of Madness!