(Note: Reading the First Warriors of Chaos is not required for the Archaon Saga.)

A thousand years ago, before Discord was imprisoned, a Warrior unlike any other rose from almost out of nowhere. Leading a vast Horde of corrupted ponies, This Warrior, Archaon The Everchosen, sowed ruination and destruction across Equestria, before being sealed in stone. A thousand years have past, and Equestria is no more, destroyed by another Warrior of Chaos named Ahriman, and his army, The New Black Legion. But Archaon has awakened from his stone imprisonment, and shall attempt to once again bring about The End Times. Ahriman's army must hold fast to defeat this foe for surely almost nothing can stop the path of destruction that Archaon walks.

A displaced story. I own nothing but the story itself. this is a Warhammer 40,000/MLP/Warhammer Fantasy Crossover.
Rated T for teen due to what could be intense violence, gore, and everything else you would expect from Warhammer.