Gallowsreign

From the Liber Reliquiarum Interdictarum, volume III, in the hand of Inquisitor Severin Aldrach
Gallowsreign is the name given to an ancient relic of which we have never possessed anything but the description, never the object itself. It is made of three materials: a leather whose origin I advise no one to look into, an ivory of which I shall say more below, and an iron steeped to its core in necrotic magic.
Those who have seen it agree upon one point, and that point alone suffices to identify it. The ivory moves. It does not move as cloth moves in the wind, but very slowly and with a regularity that lends the whole the appearance of a living thing, and none of our brothers has been able to look upon it for long without feeling an unease he was never able to name.
Let a man beware the one who wears it, but let him understand also that the wearer does not fully master it. I shall not go so far as to claim that it possesses a will of its own; I shall say only that the formulae commanding its powers belong to tongues no longer spoken, because we hunted them down and extinguished them across the ages, and that a wearer therefore never has at his disposal more than the portion he has managed to learn.
Our brothers versed in the arcane arts have observed more. The necrotic magic in it is bound to a dimensional magic, which ties the relic to its master's laboratory. It would therefore be conceivable to trace the armour back to the necromancer himself, but we have never held it long enough to take the mechanism apart, and I set this path down here so that others may follow it after me.
There remains the gravest matter. The wearer gains access, through the Damned he animates, to a knowledge sealed within the relic. The Order has faced several wearers of Gallowsreign in the course of its history, and every one of them, without exception, already knew the strategies we employ against each of its spawn.