The Steel Ministry is the priesthood for the Lord Ruler. Despite being clergy, they are not responsible for spiritual matters, but rather the bureaucracy, and policing of the Final Empire.
The Steel Ministry is large, with a wide range of responsibilities and many different types of officials. An acolyte receives tattoos around his eyes, indicating the canton in which he serves. As he gains rank, he gains additional facial tattoos.
The Steel Inquisitors form the Canton of Inquisition. An Inquisitor is the ultimate fighting machine. Bestowed Hemalurgically with all the Allomantic powers commonly known during the Final Empire as well as some of the Feruchemical powers, they are some of the most powerful creatures in the empire.
Among the hemalurgic spikes that an Inquisitor receives, two are driven through the eyes of each Inquisitor. It is unknown whether this positioning is necessary for the effectiveness of the hemalurgy, or whether the Lord Ruler simply wanted to inspire fear in the public by the gruesome effect this had on the Inquisitors' appearance. Regardless, this left the Inquisitors without eyes, but still able to see through constantly burning Steel and/or Iron. This burning, hemalurgically enhanced, allowed them to "see" even the faintest traces of metal: in the ground, in buildings, and even in people's bodies. This gave them the ability to see, after a fashion, almost everything that normal people saw, though with certain limitations and enhancements.
The Lord Ruler built weaknesses into all his creations, including his Steel Inquisitors. Inquisitors can be controlled by very powerful Soothing, leaving them vulnerable to Mistborn with duralumin. In addition, the Lord Ruler did not give them all the powers hemalurgy could bestow, limiting their abilities. Their largest weakness is the large spike between the shoulder blades of every Inquisitor. This spike ties together the two spikes through the brain and the spikes in their torso. If it is removed or the link is broken, the Inquisitor will die. Decapitation or crushing the head will break the link.
Potential Inquisitors are selected from the members of the Canton based on merit and Allomantic ability. The group paid special attention to Mistborn or Seekers amongst the Canton, since such individuals would become capable of piercing Copperclouds upon their conversion. Piercing copper is vital to their objective of seeking out half-skaa Allomancers who think they're hidden by Smokers.
After the death of Lord Ruler, all surviving Inquisitors came under the control of Ruin as a result of their numerous amount of spikes. Unlike Kandra or Koloss, they had very little control over themselves under Ruin's influence, whereas Koloss could break away from him in a blood-frenzy, and Kandra could pull out their spikes if Ruin tried to control them. The Inquisitors worked toward its goal of destroying all life. To facilitate this, they were ordered to attack the remnants of the Terris people in order to create additional spikes charged with feruchemy. A few Inquisitors also gained additional allomantic powers associated with the previously secret higher metals, through the death of mistborn.
The Lord Prelan is the head obligator. He is the head of the Canton of Orthodoxy, which is given charge over all the other cantons. This makes him the head of the whole Steel Ministry. During the last days of the Final Empire, Tevidian, the last Lord Prelan and Vin's father, was executed shortly before the Lord Ruler fell.
An Obligator is the most common official in the Ministry. Obligators are consulted on every issue the nobles need, from business deals to marriage. They collect a tax for these legal issues, helping fund the Lord Ruler's armies.
Soothing Station Obligator
Throughout skaa neighborhoods in the Final Empire, especially Luthadel, soothing stations are set up to regulate Skaa emotions. These stations are filled with Soothers, who spend their days dampening the emotions of skaa to keep them docile. Soothing stations are largely responsible for the relatively small number of skaa rebellions, and for the difficulty the rebellions have had with recruiting.
The responsibilities of the Steel Ministry are divided among the Cantons. Each Canton has a specific purpose. They are located throughout the Empire. It is implied that the Steel Ministry is vast, with many cantons, though only a few are specifically mentioned.