Adeptus Custodes - Magisterium and Misericordia: One of the singular features of the ancient Adeptus Custodes as an organisation, and the power of its individual Custodians, is their place in the scheme of the Imperium's law. While an accredited Imperial planetary governor is effectively tyrant of their own world within the edicts and parameters of wider Imperial Law, and few would gainsay the Adeptus Astartes in any demands they were to make, the Adeptus Custodes are alone officially afforded the power of the Magisterium Lex Ultima in the high form, which is to say they are beyond all law and all command save for the direct authority of the Emperor Himself. In addition to this, each one is a noble lord of the Imperium in their own right. This fact is symbolically represented not only by the right to still carry the single-headed raptor and lightning bolt heraldry of the Unification Wars campaign, but also by the carrying of the Misericordia.For long standard centuries of unbridled internecine carnage on Old Earth during the Age of Strife, the Blade of Mercy or Misericordia came to represent the complete power of life and death the techno-barbarian warlords held over the mass of Humanity which toiled beneath their yolk and suffered at their whim. From the dust wastes of Ursh to the Manakonite Temples of the No'rad ice hive, the bearing of such a blade, usually in the form of a long dagger or short sword made to perpetrate a single, killing thrust, came to symbolise the dread authority of the executioner-judge.Beyond the power it represented, the Misericordia might also be used in practice to carry out a "clean" sentence of death on a transgressor, or to offer terminal surcease to a warrior grievously wounded in battle at their master's discretion, in either case living up to its name as an agent of mercy as well as death. When the Emperor came to mastery of Terra and ended the bloody cycle of the warlords' reign, His agents and judges, and only they, came to carry the Misericordia as His mastery eclipsed all others, and it is a tradition the Adeptus Custodes still uphold.When an aspirant ascends to the ranks of the Adeptus Custodes, they are presented with a beautifully fashioned knife known as a Misericordia. These weapons are filigreed with gold and theldrite, their hilts moulded to the owner's unique grip and their blades imbued with micromolecular dissonator Machine Spirits that allow them to slice through the thickest armour as though it wasn't there at all.More than a lethal sidearm, the Misericordia signifies something greater. As the Emperor led His wars of unification, his Custodians are believed to have co-opted the term for their own use. No longer would the Misericordia be a symbol of tyrannical rule. Instead, it came to represent the right of the bearer to act as the arbiter of the Emperor's judgement, and to put to death those tyrants, lunatics and demagogues who stood against Him.The Misericordia still shows its wielder to be the Emperor's sanctioned executioner, yet since His fall these blades bear a second, grimmer meaning. They have become weapons of vengeance, to be turned upon those who betrayed the Emperor and left Him a broken shell. Every time a Misericordia is plunged into a Traitor's heart, so it is said, a minuscule measure of revenge is exacted on behalf of the Emperor Himself.Though the Custodians are typically immune to such superstition, there are those amongst their ranks who harbour the hope that if enough Traitor blood is spilt with these blades, it may in some way restore their master. Another school of thought, the adherents of which are known as the "Miserians," believe that through the wounds inflicted with Misericordia they will slowly bleed the great descendants of Horus, inflicting a death by a thousand cuts upon the Black Legion and their masters. Thus, though Custodians have the right to carry their Misericordia or not as they see fit, it is rare indeed that they go to battle against the Heretic Astartes without these blades at their hips.