This is the story of a brony, who inserted into Equestria.
But instead of a pony, he became the enemy of Celestia.

Would he decide to do what’s right, to love and tolerate
Or would his evil changeling nature make it hard to integrate

Then there is the question of the duty that is his natural birthright
Tasked by the changeling Queen, he was to murder Princess Twilight

So, here’s my attempt at a SI with a bit of a twist that others have done before. Go to Equestria, end up on the wrong side of the tracks, and have to deal with it. Enjoy!

Art provided by SoukiTsubasa

This story is a sequel to Days of Wasp and Spider

Believed dead by their creators, the ponies that will become Celestia and Luna have broken their mental conditioning and escaped into the wilderness. Here they plan the revolution that will free all ponykind, knowing that it is only a matter of time before their ruse is discovered.

Back in their underground arcologies, the ponies' erstwhile masters deal with the consequences of the escape, all the while unaware that something lurking at the bottom of space-time wants them all dead.

A Soot-Covered World, book 2.
Canon species only/no humans.
This story has nothing to do with the Holocaust.
Art by InLucidReverie, used with permission.