The Dark Legion is the single greatest threat humanity has ever faced. An extradimensional force that poured into the solar system, awakened and unleashed by mankind's unquenchable desire for conquest and dominion, its hordes of demonic aliens, necrobionic creations, mutated and resurrected humans, and misguided heretics threaten to scour the inner planets to dust. Chief amongst the Dark Legion's Apostles is Algeroth, the Master of Dark Technology and the Lord of Destruction. From the necro-vats and distortion chambers in his Citadels march an endless horde dedicated to humanity's eradication.

Algeroth enters the conflicts of Warzone Eternal lead by hordes of Undead Legionnaires, the genetically-refined super soldiers of the Necromutants, the malevolent field generals of the Centurions, and the Razides, monsters of metal and black iron, muscles and blood.