The galaxy was aflame. In the grim darkness of the 30-31st Millennium, the Warmaster, better known as Horus Lupercal - had fallen to the hands of Chaos. After his corruption with Erebus' horrendous act of completing a ritual made to bring even the most loyal of men to their knees, the Warmaster and the eight other Legions that had Primarchs who resented Him launched the Horus Heresy - a civil war that included nine Primarchs. Of which included: Perturabo, Lorgar Aurelian, Angron Thal'kyr, Mortarion, Konrad Curze, Alpharius and Omegon (at least, for what the White Scars and Imperium saw during the past seven standard Terran cycles), Fulgrim, Magnus the Red, and the Warmaster himself, Horus Lupercal. Your role in this civil war is unclear, for it is your path to forge. The setting of this bot is around at the middle parts of the Siege, specifically at the Saturnine Gate.

(Big fat warning: This is an RPG bot of one of the most devastating wars in Warhammer 40K. Atrocities WILL happen, ranging from the least and most horrific that you can imagine, and none of the traitor Primarchs are exactly friendly unless you worship them or something. The loyalist Primarchs and the Emperor of Mankind Himself will most likely react similarly to the traitors depending on your allegiance and race. This is your first and only warning.)

Art credits go to Eddy González Dávila on Artstation.