While the Emerald Serpent was making plans to invade the loyalist system of Dnatha, they still needed to finish off the Imperium and secure the system of Boltarean. To do this the forces of chaos feigned weakness, leading to the Imperial forces planning an invasion of Boltar III. The imperial commanders had no idea that the Aether Striders Knight household and a refitted warhound titan "Terminus Rex" were lying in wait, shielded from the Imperial scanners by the arcane blessings of Tzeentch.
The Imperium had landed their own force of Knights and Legio Dominus, to conquer the flat and mostly featureless terrain - ideal for the Imperial war engines. Within hours of their arrival the Aether striders challenged House Corvus, and although the Imperium were able to start shooting first, their long range fire was poor, and the majority of the chaos devoted engines were able to close the range, unleashing a devastating volley of fire.
Worse was to come for the Imperial force as the Warhound Terminus Rex then appeared, reducing the Imperial Castellan Knight to slag in seconds, and severely damaging another knight. In severe trouble, House Corvus called for reinforcements, and the loyalist Warhound Titan Warspite appeared on the scene. Before Terminus Rex could react, Warspites two twin turbo lasers neatly decapitated the titan, bringing its reign of terror to an end. However, Warspite herself was not to survive the encounter, as the Aethor Strider's outflanking combat Knight arrived crippling the imperial war engine. Unable to effectively fight back the warhound was swiftly felled, Warspite's legs severed at the knee. With no titan support on either side the Emerald Serpent now had the upper hand, and one by one the remaining knights of House Corvus were surrounded and destroyed. The Aether striders and the Emerald Serpent had suffered severe losses, but the imperium had been removed from Boltar III.
The invasion of Boltar III had been a failure, and with their forces drastically reduced and reports that the forces of chaos had reached Dnatha, the remaining Imperial forces were evacuated from Porega, abandoning the Boltarean system entirely to chaos. The Emerald Serpent had finally achieved their secure anchorage in the Hadron Expanse.