Deathmarks

Even in the days when they wore flesh, the necrontyr who would become Deathmarks were prized for a chilling combination of patience and precision. Reforged as undying metal, those traits have been honed into something inhuman. Deathmarks are the tomb legions' master assassins, hunters who stalk their quarry not across the battlefield but from a hidden dimension that lies alongside it, watching and waiting until the perfect instant to kill.

Through hyperspace oubliettes, a Deathmark squad withdraws into a pocket realm suspended between one moment and the next, a grey nowhere from which they observe the unfolding battle unseen. From there they can even intercept an enemy's own transmissions, gathering the intelligence that will guide their strike. When a target is chosen, a Deathmark brands it with a shimmering green halo, a mark that lets the assassin track its victim through darkness, fog, solid walls or open sky, no matter how far or how fast the doomed creature flees.

Their weapon is the synaptic disintegrator, a rifle of merciless accuracy. Those slain by the first shot are the fortunate ones, for a hit that fails to kill outright destroys so much of the mind that the survivor is left a hollow echo of what it was. Deathmarks favour the moment an enemy's reinforcements arrive, materialising from nowhere to cut down commanders and reinforcements alike before vanishing once more into the space between.