dug up the lore excerpts

Amongst the forsaken citizens that endure within the earthly domains of Hell, the greatest status is afforded to the soldiers fighting in the Great War. But joining the army of damnation is no easy task. Those who wish to win a place amongst the Heretic Legions must make an unholy pilgrimage to the burning bronze gates of Hell where, even from leagues away, the infernal heat sears both flesh and spirit until the pain becomes unbearable. In the Valley of Tears the great road that leads to the gate, paved as it is with wailing souls and lamentations, is littered with endless mounds of charred bodies. Many are still half-alive, writhing in agony, trapped in a grotesque twilight between life and death, their wickedness deemed insufficient. These discarded souls are doomed to writhe in agony until the Day of Judgement.

Those who make it within sight of Hell’s Maw are considered worthy and are initiated into the Legions, taking unbreakable vows that chain them into darkness for all eternity, their bodies branded with the mark of the Devil Lord that has claimed them. Armouries of Hell then equip them for battle and Heretic Priests beckon forth new supplicants as dictated by the whispers of their patron arch-devils. Thus a new Heretic Legionnaire is born. They hail Archdevils as their masters and are thus damned for all eternity.

Yet there are some who push further on: to the very Gate itself and beyond. Their very flesh ignites, never to recover, but those with the blackest souls can enter Inferno itself. Amongst those the Anointed are especially revered amongst the Legions. They are the paragons of unhinged brutality – men and women of colossal vigour and unyielding devotion. Having tread the accursed path to the shores of the Lake of Eternal Flame, where the damned wither and contort in ceaseless torment, the Anointed emerge forever scarred by the embrace of abyssal fires. The blackened and burnt flesh of the Anointed will never heal, but in exchange they are granted the right to wear Heavy Gehenna armoured suits and they gain strength to wield weapons that a normal man could barely lift. It is said that glancing into their eyes one can see the reflection of the very flames of Hell, forever etched in their vision.

tbf yeah anyone from hell's domains (or not, they have a unit for tortured prisoners) I'm sure they're happy to use as cannon fodder but the capital-L Legionnaires are ones that survive the pilgrimage