Voidblade
Somewhat of a oddity even for the Necrons.
A Voidblade is a form of Necron melee weapon, whose gleaming black edge flickers in and out of existence, causing molecular bonds to sever in any foe unfortunate enough to be struck and potentially causing a chain reaction of atomic disintegration.
A Voidblade is capable of piercing any form of infantry armor when this occurs, and its strike has a similar effect to the entropic bite of a Canoptek Scarab upon infantry and vehicle armor. Voidblades are weapons found almost exclusively as part of the armories of Necron royals like Necron Overlords, Necron Lords and Necron Destroyer Lords. However, Triarch Praetorians also often pair a Voidblade with a Particle Caster as an alternative armament to their usual two-handed Rod of Covenant, whilst Canoptek Acanthrites have Voidblades as tail-mounted close combat weapons.