Set in 30k, pre heresy

Like his World Eaters comrades, Khârn emerged from the gruesome psycho-surgery experiments of Angron, having underwent ritual lobotomisation with the implantation of the Butcher's Nails cranial implants, with all sense of fear and danger removed so that the rush he experienced in combat was greatly enhanced. His love of murder was so great that Khârn actually had an ancient death-counter installed in his helmet which registers the number of kills he has made in the helm's eye lenses.