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.

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 Spiders and Magic: Rise of Spider-Mane

Officially Complete!

A collaboration done with Azu.

With the Green Goblin defeated, Peter Parker and Twilight Sparkle are ready to take on their greatest challenge yet: parenthood. They have eleven months to prepare. In the meantime, they’ll also have to earn the trust back of everypony in Equestria, survive Twilight’s hormonal outbursts, deal with Black Cat’s antics, endure Trixie’s sarcasm, and work up the courage to take the next important step in their lives.

Cover image done by Black Freya

Officially complete!

Trouble is brewing in Equestria, and Spider-Man is summoned to save the day! However, he takes the form of a pony upon his arrival and slowly starts to lose his powers. Now as Peter Pony Parker, he must become Equestria's new hero as the Amazing Spider-Mane, but with past failures haunting his mind, will somepony be able to give him the happiness he deserves and save him from a prophecy that ends with his death?

Across Equestria and through Earth, two hearts will join together, but one may die to ensure the survival of reality...

Cover image drawn by jmkplover and colored by Saljian

Official Theme Song done by XAVI- Playful Banter

It even has a Tvtropes page!

Spiders and Magic: Rise of Spider-Mane

This story is a sequel to Spiders and Magic II: Eleven Months

Officially complete!

During a time of peace, Peter disappears in what seems to be an accident and is pronounced dead. However, he wakes up in a distant future where Equestria is in ruins, most of his loved ones are either dead or captured, and the world is under the rule of Empress Chrysalis. Spider-Mane must reunite with what remains of his friends to save this tattered future, all while desperately searching for a way to return to his original timeline.

*Thanks to Kestrel, Darth Cygnus, Commander Stelios, Regreme, Vandenbz, Lord Lycaon, The Slending Angel, cosmic flash, Derp McShirk, NeilHD, and Dark Seqvus, for editing!

Collab with Azu
Cover art done by JinZhan

Featured: 2/28/2015 -3/2/2015 (Thanks, everyone!)

This story is a sequel to Spiders and Magic III: Days of Friendship Past

Mini-series sequel to Days of Friendship Past. Discord decides to swap places with a version of himself from a parallel dimension where everypony’s genders are mirror opposites. Eris uses her freedom to reside elsewhere while her male counterpart has his fun, and what better place to go than Discord’s dimension? Neither Peter or Patricia Parker are ready for what follows…

Similar, yet different.

Featured 6/19/2015 - 6/21/2015! Thanks, everyone!

*Thanks to Kestrel, Darth Cygnus, Commander Stelios, Regreme, Vandenbz, Lord Lycaon, The Slending Angel, cosmic flash, Derp McShirk, NeilHD, and Dark Seqvus, and Azu for editing!

This story is a sequel to Spiders and Magic III: Days of Friendship Past

Every hero rises, but they eventually fall.

This is how Spider-Mane died.

Featured: 9/25/2015 - 9/26/2015

*Thanks to Kestrel, Darth Cygnus, Commander Stelios, Regreme, Vandenbz, Lord Lycaon, cosmic flash, Derp McShirk, NeilHD, and Dark Seqvus, for editing!

Collab with Azu

Cover art done by BlackFreya

It has been ten years since the defeat of the Changling Queen, and Equestria is again at peace. Twilight Sparkle and the Elements of Harmony have reached their prime, and have begun to settle down. Love and life abound in Ponyville, especially for Twilight's friends, but she has nopony to call her own.

There is a reason.

A series of events lead to a horrible revelation, and Twilight is thrust deep into a terrifying web of secrets and lies. Her peace is over.

This time, however, she won't be fighting monsters or madponies. What she faces will be much, much worse.

Act One of Two.

Act Two is here.

Currently undergoing editing by the wonderful Mstar!

This story is a sequel to Lines and Webs

For four long years, Celestia's apprentice Twilight Sparkle, once a model pony and a hero among heroes, has waged a bitter and secret struggle with her onetime mentor. Though she works from the shadows, directing her forces from the Old Capitol in the Everfree Forest, Twilight Sparkle is unable to gain any advantage,

Likewise, Princess Celestia finds her once-faithful student far more cunning and elusive than she had anticipated, and even now searches for a way to bring Twilight Sparkle's rebellion to its knees.

It is a game of greys, of knives in the dark and of poisoned wine, where pawns are moved and traded and exchanged for greater advantage, all the while drawing both sides nearer to the conflict which shall tear Equestria in two.

At the center of this conflict is a new pawn, one who only wished to see the truth for herself. Drawn into a deadly game whose rules she does not understand, Sweetie Belle must learn to survive in a world where all is darkened, and nopony can be completely trusted.

Because when gods play chess, all pieces are expendable.

A nation will crumble, old enemies shall return in the most unexpected ways, and regardless of who is victorious, only one thing can be certain.

Nothing shall ever be the same.

Followed by Stormsinger.