Cruelty of Geoffros
It was originally wielded by the Crimson Fists Space Marine Geoffros, when the Invasion of Rynn's World occurred. However Geoffros was elsewhere serving under an Inquisitor at that time and he asked to be allowed to go to the aid of his Homeowrld. The Inquisitor refused his request, though, and instead sent Geoffros to the Hive World Turren Primus, to hunt down a Heretic within Hive Qualitas undercity. This caused Geoffros to become gripped with madness and he used his Stormbolter to slaughter every underdweller he found in Hive Qualitas. It is not known what became of the heretical Geoffros afterwards, but his Stormbolter, now named the Cruelty of Geoffros, was later found by the Blood Ravens, during the Second Aurelia Campaign.