Power Scythe

The Power Scythe is a two-handed melee weapon that seemed to disappear during the Great Crusades, the power scythes never established itself and was finally discontinued by Munitorum edict in M34. It still remains popular with the Chaos legions and their human allies however, specifically for those who follow the Plague God Nurgle. This power weapon has a further reach than many power weapons, and its long blade can cut a swathe of deadly energy, slaying several foes in one arc.

Source

 * Black Crusade (Core Rulebook), p. 165