On the killing ground of Isstvan III during the Horus Heresy in the Warhammer 40K setting, there were World Eaters Space Marines on either side of the conflict who succumbed utterly, devolving into mindless frenzied savages that could not be controlled. Rather than ‘putting down’ such individuals as had happened in the past, the Apothecaries had the mad subdued and chained for a far darker fate.

The Techmarines made customised Terminator suits from recovered wargear for them, fashioning them as both armour and as confinement; mechanised prison cells that could be immobilised with a remote signal. Hung in chains in the holds of the World Eaters warships, foaming and screaming in impotent rage, the Red Butchers were born.