Strictly speaking, the last time Vulkan had fought Angron dated back to the distant Isstvan V Campaign.
At that time, the Sons of Horus, Emperor's Children, Death Guard, and World Eaters, who had already openly betrayed the Imperium, had just used the Isstvan III Campaign to purge the loyalists within their ranks.
The three loyalist Legions—the Salamanders, Iron Hands, and Raven Guard—had come to suppress the rebellion under the Sigillite's orders.
Though it appeared to be an unfavorable battle of three against four, the reality was not so simple.
The Emperor's Children, who had suffered the worst internal losses, had lost nearly a third of their numbers, while the other traitor Legions had also taken grievous casualties.
Those loyalists who had held Isstvan III for three months had more than fulfilled their duty.
They had not only sent out word of the traitors, but had also done everything in their power to weaken the traitor Legions' living strength.
But once the four Legions that had effectively turned traitor while concealing it on the surface arrived, the balance of the war completely collapsed.
Corax fled, Ferrus was beheaded by Fulgrim, and Vulkan himself was killed once by an Iron Warriors nuclear bomb, only returning through his nature as a Perpetual.
In the wars that followed, Vulkan had remained out of action. After eventually returning to Terra, he had been granted the Talisman of Seven Hammers by the Emperor and stationed beside the Golden Throne.
Vulkan had only heard of Sanguinius's glorious achievements—banishing Angrath, Ka'Bandha, and Angron, the three mightiest champions of the Blood God, in succession.
But when he looked directly at Angron again, he found that this brother had changed beyond all recognition from the man in his memories.
The Angron of old had been cold and solitary, suffering the