The Horus Heresy is a success. With the fall of the Imperium of Man came the birth of the Chaos Imperium. As more and more of the multiverse is corrupted by the Dark Gods, a single Roman Emperor pledges his world to the Ruinous Powers.

The Roman Emperor realizes the importance of the world of Equestria, as the local space is stable enough to permit successful warp travel to universes that were thought impossible to reach!

Notes:

Takes place before Season 2 Finale and four years after the Horus Heresy

Alternate History where the Horus Heresy is a success with Horus still dying

OCs included

Shit WILL hit the fan

Multiverse setting/ NO CANNON WELDING!!

Heroes:

Link (Legend of Zelda)

Pit (Kid Icarus)

Samurai Jack (Samurai Jack)

Chapter Master Raldoron (Blood Angels) of the White Templars

Samus (Metroid)

Soap (COD: Modern Warfare)

Holt (MOH: European Assault)

Gandalf (Lord of the Rings)

????

????

????

Forces of Order:

Imperium Remnants

Eldar in Exile

Jedi Exiles

???

Armies of Duty and Honor (COD and MOH)

???

Villains:

Roman Emperor Constantine (Daemon Prince, historical person)

Roman Sorcerer Vorpal (Chaos Sorcerer, OC)

Julius Augustus (Chaos Lord, OC)

Akiba Shinrikyo (Human Cultist, Melee oriented Warp-spider, OC)

Diehard Longshot (Engineer, Sniper, OC)

??? (Card-based anime)

??? (One of the longest anime in existence!)

Forces of Chaos:

Chosen of Rome

???

So, the Legions of Rome, empowered by the powers of Chaos stage a full-frontal assault of Equestria! However, hope is NOT LOST! Freedom fighters from all over the Multiverse have rallied to the defense of Equestria!

Victory can only be gained from one side through the total annihilation of the other!

TV Tropes!