Obsidax

The Obsidax is a unique Necron weapon currently in the hands of Kutlakh the World Killer. Since before the time of the revolt against the C’tan, this specially-crafted midnight-black Hyperphase Blade has been carried by the greatest war leaders of the Maynarkh Dynasty, and has ended lives without number across the ages, and its edge is bathed in a dark radiation deadly to all living matter