The entire star system containing the portal was surrounded by a Chaos rift torn open by Tzeentch. Daemons charged toward the portal from every direction, and the battle across the system had descended into utter chaos. Even when Primarchs personally commanded their Legions, the ever-changing tactical hololiths could leave them disoriented for several seconds before they found the crucial point to defend.
This chaos was exactly what Tzeentch wanted. It would create unpredictable gaps in the defensive lines established by the Space Marine Legions, allowing His daemon armies to approach the portal and threaten The Emperor's mysterious plan.
However... the alliance between the gods was not as close-knit as Tzeentch had imagined. As the master of war and slaughter, Khorne had long since grown sick of Tzeentch's wanton meddling with the battlefield. He did not care what The Emperor was doing, nor did He care what Tzeentch feared. There was only one question He cared about—whether He could watch a magnificent war that made His blood race. As things stood, Tzeentch had dashed that hope. He had thought He would see elegant scenes of Primarchs and Greater Daemons tearing one another apart. Instead, He could only watch Primarchs being run ragged by the convoluted battlefield, while His own daemons wandered through the confusion, unable to find a direction in which to kill.
How boring! How blasphemous! How unstimulating!
Upon the Brass Throne, Khorne gripped the armrest in fury. His rage made blood rain from the skies of the Realm of Blood.
"This is too chaotic!" Khorne roared. "This is not war at all! It is a pot of muddied plague soup! I cannot see armies facing one another, cannot see direct combat, only all manner of stupid ambushes and infiltrations. I even saw those idiots under Slaanesh stop attacking and