After killing Ollanius, Horus turned back to the Emperor's body and saw Garviel Loken before him. Loken pleaded with his father to prove that he was always the better man and prove he was not a slave to Chaos as the Emperor had accused. He pointed out that the Emperor had rejected to fully drink from the warp to become the Dark King and that Horus was the one being controlled by the Dark Powers. Loken appealed to Horus' pride, convincing him to briefly shed off his tremendous Warp powers and finish the Emperor as a mere Primarch. Horus, perhaps in his arrogance, agreed to do so since the battle was over anyway. Horus briefly cast off the powers of Chaos and crushed in the Emperor's skull with Worldbreaker as the Chaos Gods and Daemons around them angrily shouted and protested, trying to warn Horus of something. Horus ignored them but was shocked to find that this was simply a ruse by the Emperor. Loken and the Emperor's corpse had both been illusions, and the real Emperor launched one last assault upon Horus.[27h]
With Horus briefly depowered and the Emperor greatly weakened, the ensuing contest became purely a physical one but the Warmaster was able to gouge out the Emperor's eye, mutilate his arm, crush his spine, and set his hair alight. The Emperor struck back, using the power of the reactivated Astronomican to shine its light directly into Horus' brain. The Warmaster fell into agony as he desperately tried to cloak himself in Warp power once more. However much to Horus' horror, he discovered that the Chaos Gods were now teaching him a lesson of sorts by deliberately denying him their power. Horus came to the realization that he had never been in control, and his Chaos masters were treating him as they would a disobedient slave. The realization combined with the brief absence of Warp corruption over his soul saw the old Horus the Emperor had once loved manifest once more.[27i]
Horus pleaded with the Emperor to kill him before the Chaos Gods could fully reassert control. The Emperor initially hesitated, but granted Horus a mercy and stabbed His son through the chest with the Athame blade Ollanius had given him. Stating that he forgave Horus and would wait for him, Emperor then channeled all of His might into the blade, obliterating Horus' form and reducing him to a mere skeleton inside charred armour. With the deed done, the Emperor immediately collapsed as the real Garviel Loken watched with horror. Furious and wailing that their pawn was dead, the Chaos Gods instantly retreated back into the shadows. The Warp-madness that had plagued Terra and the Vengeful Spirit went with them and conventional space-time was restored.[27i] Aftermath
Main article: Great Scouring
Shortly after Dorn, Valdor, and a small Custodes escort arrived in Lupercal's court to find Loken and the two corpses. Leetu had also lived through the ordeal, and directed Dorn as to where to find Sanguinius' body and Ferrus Manus' skull. Both alongside the Emperor's body were taken by Dorn and the others as they teleported back into the Imperial Palace. Loken insisted he stay behind to watch over his fathers body, something that later caused him to be killed by Erebus.[27g] Back inside the Throneroom, Leetu pointed out a Throne Tarot Card had been discovered by the Emperor's body. Dorn and even Valdor both agreed this was a sign directing them to place the Emperor upon the Golden Throne once more. Malcador's form upon the Throne had since disintegrated into nothingness.[27j] The Emperor has spent the last 10,000 years upon the Golden Throne, eternally silent.[1e]
Immediately upon the death of Horus, the situation on Terra reversed completely. Every Daemon across Terra was sent back into the Warp as the Chaos Gods recoiled. Guilliman's fleet arrived in the Sol System, bringing massive amounts of reinforcements and beginning a vicious counterattack alongside Admiral Niora Su-Kassen and The Phalanx, which emerges with its escorts from hiding within the rings of Saturn to attack the traitors. With their Primarch dead, the Sons of Horus fell into complete disarray and immediately broke, with Abaddon gaining some groups of survivors and fleeing aboard the Vengeful Spirit. Many of the more corrupted traitor Space Marines died where they stood, while others fell into a fugue state. Panic broke out amongst the lesser followers of Chaos.[27h] Most either met swift end to the Imperial counterattacks or attempted to flee the world in whatever ships they could find.[31a]
Though massively outnumbered, the small group of loyalist survivors led a spiteful counterattack that chased the Traitors out of the Palace and soon all of Terra. Over the ensuing days the Traitors were completely routed.[27h] Once Guilliman's force arrived in orbit, all hope of an organised Traitor withdrawal was lost.[31a] Despite most attempting to flee, some isolated Traitor contingents would continue to resist for quite some time on Terra, with a sentient Obliterator Virus even unsuccessfully attempting to turn the tide by spreading its infection from the Lion's Gate Spaceport to the arriving Ultramarines fleet.[29] While it is said that the Sons of Horus were the first Traitors to flee the Throneworld, the Death Guard were thought to be the last.[6]
Amid the panicked retreats and final stands by the Traitors, the Ultramarines fleet in orbit was obliterating their fleet, creating massive casualties. Guilliman set foot on the Throneworld shortly after, meeting with the surviving loyalist Primarchs: Rogal Dorn, Jaghatai Khan, and Vulkan alongside the newly arrived Leman Russ and Lion El'Jonson.[31a] They then destroyed what remained of the Traitors on Terra, and even before the fighting was done Guilliman and Rogal Dorn organised the Grand Council of Reconstruction within the ruined Imperial Palace.[31b] Remaining pockets of Traitors attempted to sneak out of the System by mostly powering down their ships to avoid detection.[31b]
Even as the Loyalists battled across Terra and its orbit, in the Council issues arose almost immediately. Rogal Dorn along with Leman Russ and The Lion wished to conduct a swift and vengeful pursuit of the Traitors fleeing the Sol System, while Guilliman wished to consolidate their holdings and rebuild their strength while taking strategically important assets such as Luna and Mars. Ultimately, thanks to support by the newly empowered High Lords of Terra, Guilliman's position prevailed and the Ultramarines focused on retaking Luna while the Dark Angels cleared out the last pockets of resistance on Terra and the Space Wolves focused on securing the Sol System and besieging Mars.[31c]
Eventually, in an event known as the Great Scouring, the Traitors were driven wholly from the Imperium and into the Eye of Terror.[1e]
000014.M31 - The Solar War begins as the Traitor armada arrives in the Sol System.[30]
119014.M31 - The Traitors begin their orbital bombardment of Terra.[30]
286014.M31 - The Fall of Helios Gate, the first section of the Imperial Palace to be captured by the Traitors.[30]
358014.M31 - The Fall of Lion's Gate Spaceport.[30]
388014.M31 - Gorgon Bar falls.[30]
390014.M31 - The Colossi Gate falls as the Traitor attack on the Saturnine Gate fails.[30]
393014.M31 - The Eternity Wall Spaceport Falls.[30]
560014.M31 - Corswain and his Dark Angels land at the Astronomican.[30]
574014.M31 - Jaghatai Khan recaptures the Lion's Gate Spaceport.[30]
588014.M31 - Sanguinius leads the stand at the Eternity Gate.[30]
593014.M31 - The Emperor faces Horus aboard the Vengeful Spirit.[30] The flow of time on Terra essentially freezes by this point until Horus is killed.[27i]