Mortarion's panicked flight was like pulling the spine from the plague army.
Without the Primarch's psychic command and intimidation, the remaining Death Guard Space Marines, Nurgle daemons, and plague zombies swiftly collapsed before the Primaris warriors led personally by Guilliman, like blue thunder.
None could halt the loyalists' advance. Every swing of the Emperor's Sword sent burning, filthy wreckage flying, while the roar of bolters rang like funeral bells.
Parmenio's defiled surface began to be covered by the flames of Imperial wrath and purifying fields. Blue, the color of hope, gradually replaced the nauseating green.
And Mortarion, the grievously wounded lord of the Death Guard, fled toward Iax without looking back, carrying endless humiliation and terror of that dreadful weapon.
He had to rendezvous with Ku'gath and make one final struggle with the Great Unclean One's power and the unfinished "Godblight" on Iax.
That would be the final battlefield where he either turned the tide or met utter Destruction.
The battle in orbit was equally swift and brutal.
The elite Primaris warriors led by Felix were like the sharpest blade, plunging into Galatan Starfort's interior.
The Starfort's vast internal structure became the site of bloody close-quarters fighting, where Death Guard Plague Marines relied on the terrain and omnipresent plague traps to resist desperately.
Yet the Primaris warriors' strength, coupled with the continuous boarding reinforcements from loyalist Chapters, gave the loyalists unstoppable momentum.
They precisely cleared key nodes, dismantled the defense systems, and, after paying a certain price, finally retook the Starfort's core control chamber, wiping Nurgle's blasphemous mark from the command throne.
"Galatan Starfort has been purified, Lord Regent!" Felix's voice was firm with victory beneath a faceplate smeared with foul blood and coolant. "Control has been reclaimed! The fleet threat has been eliminated!" He paused, regret entering his voice.