Plague Marines form the core of every Death Guard host, the shambling rank and file upon which all their campaigns are built. Once proud Space Marines, they have been hollowed out by the Grandfather's gifts and stuffed full of maggots, gas, and corruption, their bodies rotting yet impossibly durable. Their armour has split and bloated around them, fused with their diseased flesh and encrusted with the residue of ten thousand years of decay.
What makes them so terrible is not ferocity but endurance. A Plague Marine ignores wounds that would kill a mortal instantly, plodding onward with limbs shattered and organs ruptured, its ruined body sustained by daemonic vitality and sheer devotion to Nurgle. Bolts and blades that find their mark barely register. They know no fear and feel little pain, and they cannot be made to break.
In battle they favour weapons of contagion and corrosion: guns that spew filth, blades slick with rot, and grenades that burst into clouds of choking spores. Simply standing near them is lethal, the air around them thick with disease. They advance slowly, methodically, an unhurried tide of pestilence that soaks up firepower and keeps coming until the enemy is dead, sickened, or overwhelmed.