When a craftworld has too few living warriors to answer the doom before it, it wakes its dead. The Wraithblades are wraithbone constructs animated by the spirit-stones of fallen Aeldari, their souls coaxed from slumber by a spiritseer and set to fight once more, this time hand-to-hand amid the press of battle.
Each construct wields either a pair of ghostswords humming with disruptive energy, or an axe and forceshield that turns aside blows which would fell a tank. Driven by a strength no living body could sustain, they wade into the enemy and strike with mechanical, tireless certainty, feeling neither pain nor terror as they dismember all before them.
There is a deep sorrow in their deployment, for every Wraithblade is a hero of the past denied its rest, its ancient spirit dulled and disoriented by the weight of the flesh-that-is-not-flesh. The spiritseer must walk beside them, whispering, guiding, lest a wandering soul forget itself entirely. They are a measure of desperation as much as strength, the price a dying people pays to endure one more day.