As was their way, the Ultramarines established footholds at defensible positions, clearing room for their reinforcements to land.
The painful memories of that day, long ago, were too much for the Primarch to bear. The scar looped around and around Angron's body, spiraling up over his belly, around his ribs, towards his chest. He chose the new name for his Legion when Dreagher, a Terran-born War Hounds Legionary who served as Captain of the Legion's 9th Company, promised Angron after meeting his Primarch for the first time that under his leadership the War Hounds would become, "...the eaters of worlds.". Taking his position as Primarch of the XIIth Legion, which he renamed the "World Eaters," Angron instigated a program of replicating the cranial implants he himself had been fitted with as a slave-warrior, knowing that the devices granted such advantages in speed, aggression and strength that no enemy in the galaxy could stand before his Legion once all had received them. Guilliman found himself forced back by the storm of Angron's blows. The Emperor and a small cadre of Legio Custodes descended to the world's surface, and after the shock of the august meeting had worn off on the Primarch, the Emperor offered Angron the leadership of the XIIth Space Marine Legion, the War Hounds, which had been created from Angron's own genetic material, and a place at his side in the Great Crusade. These names would then be entered into the ship's Archive of the Fallen; other Legions used different names, such as the Thousand Sons' Dirge, or in the case of the Sons of Horus, the Lamentation. However, this proved difficult, for Angron's implants were a relic of a long-lost human technology and little understood. Guilliman had seen the ramp of World Eaters corpses that had been used to finally mount a breach in the mighty fortress and the vengeful horror the Space Marines had wrought within and been sickened. No one ever saw who fired the first shot.
Since the day of the War Hounds' founding, whether the foe before them was xenos, machine, or even the Emperor's own Thunder Warriors, the XIIth commenced hostilities according to their own fashion. Bringing His flagship into low orbit over the world, the Emperor teleported Angron from the surface against his will, away from the mountain of Fedan Mhor and the Battle of Desh'elika Ridge. It is not known if this world was their Primarch's homeworld or not, but popular belief was that it was indeed the world on which Angron had been a slave. At the summit of Fedan Mhor, Angron and his brothers prepared to make their stand. Forcing Khârn's hand, the Eighth Captain confronted the enraged Daemon Primarch himself.
The moment Guilliman's boot broke the skull, he felt the Warp boil behind the veil. Angron gave his psychic sons a choice between execution and the removal of their Butcher's Nails implants.
The first Drop Pods hammered home on the planet's surface. With both the Dark Angels and Space Wolves Legions on their way to Terra to reinforce the Loyalist defenders, Horus gambled everything in order to win the siege, lowering the Void Shields on his flagship, the Vengeful Spirit, and daring the Emperor to come aboard and face him. Rank is disregarded, and all that matters is the weapon in their hands, and who strikes first. Legionaries of other Legions often told tales of how they have never met a single World Eater without at least one metal tooth jammed into his gums, and most sport whole sets from their time in the gladiatorial pits. These simple, unarmed constructs used their sheer numbers to swarm the Astartes, killing Space Marine after Space Marine no matter how many simulacrums were destroyed.
While the World Eaters flagship was busy repelling boarders, a number of smaller XIIIth Legion vessels slipped past her defences and launched Drop Pods, gunships and troop carriers. Bodt was seized by the legion during their early days, an…
The diffuse nature of the World Eater Legion means that, in practice, each grand company retains a great degree of independence.
Other offers may also be available. On the occasions it was brought into battle it performed with almost gleeful savagery, tearing apart whatever enemy it was given to fight without mercy or falter, regardless of its own losses and heedless of the risk. Angron was plastered with the blood of the slain after hours in the crush of the front lines of intense combat. The "Black Knight" they had called him, in honour of his prowess, his nobility and his personal heraldry. This hazardous treatment allows World Eater marines to control their responses, emotions and autonomic reactions beyond that of other legions, in line with their compulsion to enforce iron-willed self-restraint on the battlefield. For some time any War Hound of his Legion who came before their Primarch was met with a grisly death for their efforts. They worshipped him for it. Now there would only be blood, an ocean of blood carried on a tide of eternal slaughter. He locked Angron's muscles, setting fire to the synapses in his brain. Ultimately the existence of psykers in the Imperium such as Astropaths and Navigators was allowed but tightly restricted under centralised Imperial control, while the potent and unrestricted use of psychic abilities that was defined as sorcery was officially banned.