During the Crusade, Kharn served as Angron's Personal advisor, often acting as a voice of reason that cooled his primarch's bloody rages, a surprising contrast with the person Kharn was destined to become. Like the other World Eaters, he underwent extensive surgery, increasing his aggression such that he now finds joy only in killing the enemy. His love of killing is so great that he has actually had a kill counter installed in the lens of his helmet. This kill counter was made from arcane technology and was a gift from the Warmaster Horus himself.
At the Battle of Skalathrax, between the Emperor's Children and the World Eaters, Kharn became both legendary and infamous amongst his legion. When the World Eaters' advance stalled, even though they were close to victory, Kharn became disgusted at their weakness and flew into a berserk rage, slaughtering friend and foe alike. Because of this, the World Eaters were completely scattered into small, individual war bands, and have seldom, if ever, fought as a unified Legion since then. Kharn's actions at Skalathrax earned him the nickname "The Betrayer", which he has carried ever since.
He wields a Plasma pistol and the ancient chainaxe known as Gorechild, which, along with its twin Gorefather, was wielded by Angron himself during the Heresy.
One plastic blister containing Kharn the betrayer supplied.