Death Guard - The Inheritance of Barbarus: Decades of endless battle changed the Death Guard, and over time the Terran influences on the Legion became less and less apparent, with the panoply and traditions of the Dusk Raiders and the Officio Militaris erased in favour of Barbarus' bleak creed of war.The bare ivory-grey unpainted ceramite that Mortarion favoured for the Legion's Power Armour became increasingly less adorned, save for new murky-jade markings set to echo the corrosive-resistant swamp mud applied to coat the iron plates of the human warriors that had once served the Primarch of Barbarus, and shorn of older heraldry and Terran influence.The martial stratifications of Old Earth's warmasters were done away with too, and eventually the Legion's Librarius was disbanded thanks to Mortarion's hatred of witchery such as that the hated charnel masters of Barbarus had once wielded.Mortarion's hand and mind was at work everywhere remaking his Legion, from changing tactical doctrines to equipment procurement and, some say, behind the selection of candidates and changing practices in the Legion's Apothecarion, where he gained the latter knowledge to interfere.With the prevailing conditions on Barbarus and the foul beings that more than likely still stalked the planet's fog-shrouded mountains and deep swamps, there were whispers that the human population that remained would have been better off if they had been euthanised or displaced to a "cleaner" world for the sake of the sanity of future generations.Mortarion would have none of this, for Barbarus now belonged to his people, bought and paid for by generations of blood and terror, and its strongest sons would now serve as recruits for his new Death Guard.As for the purely human Death Guard that had once fought for him against the overlords of Barbarus, many now became the masters of that world and a dread aristocracy they soon became, while the youngest and strongest took full or partial conversion into the Legiones Astartes, heedless of the high fatality rate that late induction carried with it, deemed a small enough price to pay to continue in the service of Mortarion their saviour.With new recruitment at issue, Barbarus itself in a short span of years became little more than a factory of sorts to produce new recruits for the Death Guard Legion, and intake from other sources of recruitment to which the Legion had title dwindled to a mere handful, unless the pressure of fatalities in the field proved too great.Mortarion's resistance to the use of bloodstock other than that of Barbarus wavered only because of the need to keep his Legion's strength battleworthy in his eyes. Recruitment solely from Barbarus was however aided by the high suitability of the planet's hardy feral population to the conversion process. The Legion's gene-seed seemed to amplify the uncommonly resistance to contagion and toxins in its Barbarus candidates to unheard of levels.As fresh intakes of new Space Marines came in from Barbarus, the surviving core of Terran blood became a minority as the Great Crusade burned on across the stars, the Death Guard at the forefront of the fighting in the most hellish war-zones imaginable. Although second perhaps in their father's eyes, the Terran contingent remained stubborn in the ranks, hardened veterans and a force to be reckoned with in the Legion.With the Legion drawing the majority of its Neophytes from Barbarus, this changed the culture and traditions of the Legion, so much so that by the last days of the Great Crusade in the early 31st Millennium, there were increasing tensions between the Barbarus-born Astartes and the Terran minority who remained in the Legion and who remembered the Dusk Raiders' earlier martial traditions brought out of Old Terra.These tensions became most clear in the period directly preceding the first battle of the Horus Heresy at Istvaan III, when approximately one-third of the Legion was judged by Mortarion to be likely to remain loyal to the Emperor when the Legion joined the Warmaster Horus in his rebellion against the Imperium.Many of these Loyalist Death Guard Astartes were Terran-born, former Dusk Raiders like Battle-Captain Nathaniel Garro of the 7th Great Company whose loyalty to the Emperor outweighed their devotion to their Primarch.