C'tan phase weapons (also known as fractal edged weapons) (including the Callidus Assassin Phase Sword, Cypher's Phase Knife, Necron Warscythes and the metal bodies of the C'tan themselves) are all based around a metal blade of unknown composition that, through the use of highly advanced Necron physics, is capable of slicing through any object irrespective of its physical properties. Energy shields, armour and even daemonic bodies are of no defence against a Phase Weapon. However, as the C'tan Necrodermis is made of the same metal and has the same properties, attacking a C'tan with a Phase Weapon disarms the attacker, as the metal becomes a part of the C'tan's Necrodermis shell.
