Appearance
In the Mistborn series, the Steel Inquisitors are described as having thick metal spikes that have been pounded, tip-first, through each of their eyes. They are described as tall, lean, and bald, wearing black robes, and sporting intricate tattoos around their eyes.
They also have a “horrifying, unnatural gaze” (1.250), and a distinctive air about them that is hard to put into words:
“Standing beside the noblemen were the obligators—ordinary ones in grey, Inquisitors in black. Vin shivered. There were eight Inquisitors, their lanky forms standing a head above the obligators. But it wasn’t just height that separated the dark creatures from their cousins. There was an air, a distinctive posture, about the Steel Inquisitors” (1.432).
Creation
The Lord Ruler created the Steel Inquisitors (along with the koloss and the kandra) many centuries ago to be his loyal servants. He used the practice of Hemalurgy to make them, inserting metal spikes through the hearts of Mistings and Feruchemists.
All Inquisitors have two spikes in the head, eight in the chest, and one in the back to seal the upper body spikes and lower body spikes together. The sheer number of spikes they have makes them especially susceptible to Ruin, the god of destruction.
Attributes
Brutality
Steel Inquisitors are brutal beings. They leave behind massacres intentionally in order to instill fear into those who discover them, the dead bodies serving as a warning signal. Moreover, they are perhaps even more powerful than the Mistborn allomancers themselves.
Healing & Strength
Steel Inquisitors can heal quite rapidly. At one point in The Final Empire, an Inquisitor has an arrowhead wound that heals in a matter of hours. Furthermore, they are incredibly strong and resilient to pain.
“She cursed, struggling as she glanced down at the Inquisitor’s bloodied leg. Even with pewter, he shouldn’t have been able to walk on it. She tried to twist away, but the Inquisitor had her in a powerful grasp” (1.592).
Vision
Inquisitors don’t need light to see; whatever strange power allows them to see with spikes instead of eyes works as well in pure darkness as it does in daylight (2.129).
Population
There are only twenty or so Steel Inquisitors in existence at the beginning of The Final Empire, nine of which are part of the Lord Ruler’s immediate employ.
Religion
Steel Inquisitors have an obvious fondness for steel; their religion is referred to as the Steel Ministry, after all (2.130).
Mortality
In the beginning of the Mistborn series, the Steel Inquisitors are said to be immortals. However, it is later revealed that this isn’t actually true.
When Marsh infiltrates the obligators at the ministry, for example, he finds out that Inquisitors change occasionally. That they are exceedingly long-lived, but they do eventually die of old age, and that “new ones must be recruited from noblemen ranks” (1.455). He describes them as people who have merely been changed, seemingly by some dark force or magic.
Killing Them
One way to kill a Steel Inquisitor is to separate its top spikes from its bottom ones. This is because the spikes in their body form a chain, with a central spike acting as a linchpin to connect the spikes in the lower and upper halves of their bodies. If this linchpin is removed, the Inquisitor will die. This was the weakness the Lord Ruler had built into them in case he needed it.
Another way to kill them, however, is to simply behead them. Kelsier is able to do this in The Final Empire. According to Marsh, “Kell did it through a beheading, but it’s easier to just pull out the middle spike” (1.637).
