"Take solace in the fact that you are aiding a tortured soul find atonement and salvation through their service to the Emperor," Commissar Larkson observes dryly. "He lives to pay penance, and without you to carry him, where would he be?"

The more simple answer would probably be "somebody's gotta carry the twist," but at least this answer will give them more motivation and possibly respect for the poor mutant who desires to fight and die to atone for what he was born into. Surely the troopers wouldn't ignore his plight for salvation in the Emperor's eyes, right? Okay, maybe...