Losing limbs or even heads is of no issue to them, for it will reconnect itself quickly. Should they suffer damage that cannot be repaired on the field they will teleport back to their Tomb World, where they will be repaired and sent once more into battle. Should they suffer losses their bodies made from living metal will repair itself quickly. Equipped with Gauss Flayers, their weapons destroy matter at an atomic level. They are automatons that cannot be destroyed by anything but the strongest heavy weapons. Their sturdy bodies make more than up for their lack of sentience. They possess little sentience, losing out the most on the mind transference. Unstoppable, slow, and silent.The mainstay of a Necron army are their Warriors. But those that kept their minds did not forget this trickery and once their common enemies were dead or fleeing, Necrons turned their awesome weaponry on the now weakened C'tan and in turn conquered their own gods. By promising servitude, the Necrontyr were given immortal, metal bodies from their own living metal, and transferred their minds, not knowing that by doing so they became mindless, soulless puppets, urged by the C’tan to harvest more life for them to feed on. After being given bodies made out of living metal, the cosmic horrors began to feed on the living, devouring their souls for the stars were tasteless, and the lives of their hosts were delicious.

These C’tan or “Star-Gods” were somehow contacted and invited to the Necrontyr homeworld. In time they discovered ancient cosmic horrors, immortal entities that fed on the very stars that lit their planets. Forgotten by their former enemies, the Necrontyr were left to their suffering. Jealous of the nearly-immortal Old Ones with whom they co-existed, a war was waged and quickly lost. In the past they lived short and painful lives, a far cry from the macabre form they possess today. Second Book of Admonitions, Inquisitor Hoth

Ancient darkness