Changelings.

To most, they are the creatures that almost took Canterlot, shapeshifters able to feed on the emotions of those around them.
While this is true, it is not all there is to the story.

When the Great War began, an alliance was struck between Princesses Celestia and Luna, of Equestria, and Queen Chrysalis, of the Changelings.
The changelings, natural infiltrators since birth, would become spies for Equestria. In return, they would no longer be hunted, permitted to continue feeding as they had for countless years before their failed invasion, provided they not engage in acts harmful to the equine government or population at large.

Of course, that was simply the beginning. As the war began to escalate, Stable-Tec, the company responsible for the life-saving Stables, recieved a request from parties that would, as part of the contract, remain anonymous and unnamed.
They were asked to create something new, something that would allow both changelings and ponies to survive, and promote harmony between the races.

They were asked to create...

Project HIVE

Broken Thorn only ever wanted to serve honorably, to work for the betterment of Equestria in the royal guard and serve Princess Celestia.
That didn't work out so well when the Balefire bombs dropped right in the middle of his first mission.
Two hundred years later he finds completing his mission to be the least of his worries. Stranded in the wastes with no friends, a pair of wings he doesn't remember getting and too many questions.
Being an Alicorn is tough.
But being the only Alicorn stallion?
Needless to say hilarity and chaos follow.

This fanfiction is based on Fallout Equestria by Kkat, whose magnificent work of fiction inspired me to seriously write for the first time in my life.