The Cerberax Wars is a series of conflicts that erupted between the daemons of Khorne and the Necrons of the Sautekh Dynasty in the wake of the birth of the Great Rift during the 13th Black Crusade in 999.M41. The conflict has spilled over into Imperial space and several Chapters of the Adeptus Astartes have been despatched to deal with the incursion.
The conflict began soon after the birth of the Great Rift unleashed the Warp Storm designated "Cerberax" by the Imperium on the Ultima Segmentum. The massive Warp Storm immediately consumed three star systems and continued to grow in size until it neared the ancient Necron construct known as the Ymga Monolith in the Attila System.
The monolith began to glow as the Cerberax Warp Storm closed on its location. The monolith created a perfect sphere of Order around itself that remained immune to the effects of the Warp Storm as it progressed across the galaxy. The Tech-priests of Mars' Holy Requisitioners thus discovered that like the Cadian Pylons, the Ymga Monolith was a Necron phase node of immense power intended to close off realspace from the Immaterium.
Thousands of Necron warships of the Sautekh Dynasty soon arrived to defend the monolith from a Warp incursion led by daemons of Khorne who emerged from the Cerberax Warp Storm. The vessels formed a defensive shield around the monolith, as it was an important asset for the Sautekh Necrons. Visions of the Imperium's Corinthe Mind-Scryers revealed that the monolith possessed the ability to physically duplicate any Necron warship that made contact with it, massively reinforcing the Necron forces in their battle with Chaos.
Solar months after it began, the Cerberax Wars spilled over into Imperial space and every world within fourteen hundred Terra-Sols of the Ymga Monolith had become a battlefield between the Necrons and their daemonic foes. The Imperium despatched strike forces drawn from the Ultramarines and Mortifactors Chapters of the Space Marines to defend the affected human worlds. However, the sheer number of daemons unleashed from the Warp by the Cerberax storm means that the Astartes may have no other choice but to enact Exterminatus actions on all of the Chaos-corrupted worlds.
- Gathering Storm - Part II - Fracture of Biel-Tan (7th Edition), Ch. 1 - "The Dance of Destiny - Addenda Inquisitoria"