Charn is voiced by Jason Singer.
Originally, Charn and his underlings were intent on a quick and effective slave-raid, but the arrival of Balak changed the entire mission. Despite harboring negative and rebellious feelings, Charn is found guarding the final fusion torch as the last line of defence. However, he wants nothing more to do with this mission, hoping only to leave; his fear of Balak "skinning him alive out of spite" nevertheless keeps him on the asteroid to confront Shepard and the squad. When Charn accosts Shepard and the crew, he tells the Commander "this doesn't have to end in bloodshed" and tries to negotiate, claiming that he and his men had only signed on for a slaving mission, not to destroy a colony.
Shepard can convince Charn to leave the asteroid peacefully, under the promise that Balak will be eliminated and Charn will then be the one calling the shots. In that event, Charn agrees immediately and provides Shepard with a pass to the main facility along with a warning that Balak is a "mean bastard".
Alternatively, Shepard can attack Charn, stating that Balak's coming to Asteroid X57 to capture slaves is "reason enough" to fight. After the fight, Shepard can simply take the pass from his corpse.