When Rarity is given an order for a dress, a series of unfortunate circumstances lead her to request the aid of Twilight Sparkle. When she discovers that Twilight has been studying time spells, she asks if she can help her recover some of her time. Reluctantly, Twilight agrees, but when she is performing her spell, something breaks her concentration causing the spell to become unstable, sending them 15 years into the future. What awaits them in a world where they have been missing for so long? Will they ever get back to their own time? Only time will tell.

*WARNING*
COMMENTS CONTAIN SPOILERS
(I LOVE feedback)

Art by Dreatos
- http://dreatos.deviantart.com/gallery/?offset=24#/d47n304
Seriously, check out his work. He is one of my favorite pony artists.

This story is a sequel to Apotheosis

Celestia leaves Equestria in the hooves of Luna and Twilight.

While she searches among the gods to answer her questions, Luna and Twilight must struggle to fulfill their own duties to ponies and to Equestria.
Now with a Spanish translation by SPANIARD KIWI: https://www.deviantart.com/spaniard-kiwi/art/Apoteosis-3-3-857110357

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.

Sort of sequel to Nightmare's Lullaby.

About a year after the defeat of Nightmare Moon, strange things are happening to Twilight. She starts to recieve strange dreams and something is... changing in her.

"Beware Her wrath, fools who dare threaten our Kingdom. For if Celestia be our Shield, then Luna is the Sword."

Spiritual companion to Sweet Celestia.

After Shining Armor falls in battle, Luna helps Cadence cope with her grief. With his death, Cadence can no longer escape the harsh reality of her immortality and must come to terms with it.

Twilight, also struck by the truth of her situation, seeks out Celestia, who offers her an answer as harsh as the truth she must face.

Despite the sad tag, I can promise that there are heartwarming moments.

Celestia is trapped on Earth.
Not as a human. Not as an alicorn. She's a common horse, an Arabian mare, without her magic, voice, knowledge of the language - not even freedom, forced to work at a riding school.

What can a single Arabian mare do to get back to Equestria from this backwater European country? With only the mind of a princess and a pencil in her teeth, Celestia must find a way home.

[Illustrated] [Alternate Earth] (without Bronies)
Rated Teen for language and some scarce suggestive themes.
Proofreading by AlicornPriest

Polish language version

After failing to stop Nightmare Moon in the ancient castle of the pony sisters, Twilight Sparkle is left with a scar that will permanently change the rest of her natural born life. As Twilight recovers from her ordeal, she finds that she is left with a difficult choice. Either live her life as a lie or sacrifice her innocence to protect the ones she loves. The path before her is set and she must now walk it alone. The sands of time continues ever onward, with everyone already trapped in its muddy depths. The sun will rise and the sun will fall. Waiting for its call, Death awaits for all.

Tags, rating, and characters can change.

Art created by:
http://cuteskitty.deviantart.com (top)
http://ventious.deviantart.com (bottom)

I just put the two together

Twilight's day hasn't gone well. Her night is about to get a WHOLE lot worse. Starting with being banished to the Moon...

After a series of unfortunate events conspire to trap Twilight within her own nightmares, Twilight's friends - along with the with aid of Princess Luna - become Twilight's only hope of rescue. Time and Twilight's fears are already against them, but they must also come to terms with how Twilight got there in the first place...

This story is a sequel to A broken Sun

It’s been three months, dear sister, three months since you left. Where could you be? I know you’re out there, I know it. Your most loyal guard and his armies have been scouring Equestria, looking for you, sister. Please, return and we can repair what has been broken and start over. Every night is a nightmare since you left. This wasn’t supposed to happen like this, please, if you can do one last thing, come back. But we will find you, Celestia, and we will mend our relationships. I’ll see to it that you are retrieved, dear sister. Mark. My. Words.

Edited by: Razalon the Lizardman
Collab with Pvt Caboose