are heavy close-combat weapons used by Chaos Space Marines
of the World Eaters
In Dark Millennium Online Edit
They are weilded by the Chaos Space Marine Class. The presumed leader of the Chaos forces, Unknown Chaos Figure, can be seen holding his own variant on the Dark Millennium Online mainpage.
The weapon works much like the Space Marine Chainsword with motorized monomolecular-edged teeth capable of slicing through armour, flesh, and bone.