A letter from Celestia interrupts one of Pinkie's parties with disturbing news. Now friendships will be pushed to the limit as Twilight struggles to uncover which of her friends is not who, or even what, she appears to be.

(While not a romance, this does contain a shipped pair)

in Russian

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

Spike gets a can of old Spice. He then proceeds to destroy the country. All explanation needed.

Many years after sending her beloved protege to Ponyville, unease sits heavily on Princess Celestia's heart as her relationship with Twilight Sparkle seems to have cooled despite all they've accomplished together. On the advice of her sister, Celestia sets out to investigate and resolve the lost connection with her most faithful student. What does it mean to be a Faithful Student...or a Princess of the Sun?

Earned a six-star rating on Equestria Daily and featured on its very own TVTropes page!.

It's been eighty-nine days since the Day of Darkness, and Twilight Sparkle is still on her own. Eighty-nine days since she talked to anyone other than herself. Regardless of how lonely she feels, she prefers the company of herself to the vicious "lurkers", as she calls them, roaming around outside of her library. Whatever friendly, loving creatures they were before the Day of Darkness, something changed them. Something created these insane creatures, and nothing, not even Twilight, can stop them. All Twilight can do is live — live to fight another day.

Derpy Hooves is secretly a changeling.

Nopony particularly notices, or cares.

(New 9/15/19: Spanish translation by Spaniard Kiwi! Thank you!)

Princess Celestia always knew that Twilight Sparkle was destined for great things, but she never revealed the source of that knowledge, not even to those closest to her. When the day of Twilight's true destiny finally arrives, can Celestia fulfill an ancient promise to save Equestia's past, present, and future, even it means saying goodbye to Twilight forever? How can Celestia refuse her mother's last wish?

Art by the inimitable Harwick

It's Sisterhooves Social time again. This year, Dash catches wind of two new competitors and gets Spike to bet on the race. When her team is revealed to be a rather famous set of siblings, it looks like poor Spike will be her slave for a week! However, due to a team of masseurs, a minor invasion, unfortunate addictions, and dubious barrel components, victory might not be as near as she thinks...

There was only one explanation. For all of it. All of the strange, erratic behavior. Her irrational fear of the sun. Her nocturnal habits of locking herself in in the dark and closing all the blinds. Wearing her sunglasses everywhere, even inside! It was time to invest in some silver, garlic, and a wooden stake.

This story is a sequel to Past Sins

Side-story to Past Sins - Spike almost lost Twilight to a hangmare's noose, but now Twilight is safe and Nyx is a filly again. Normal life is returning. Still, Spike can't ignore the fact that Nyx just isn't the same as he remembers her. Her temper is more volatile, and, when she gets angry, all he can see is the rage-driven Nightmare Moon of legend.

And thus Spike has to wonder: Is Nyx truly reformed, or is she one bad tantrum away from calling herself Nightmare Moon again?