The Steel Inquisitors are the Lord Ruler's most feared enforcers - terrifying figures with steel spikes driven through their eyes who serve as the religious police of the Steel Ministry. Created through Hemalurgy, each Inquisitor carries numerous spikes that grant them a devastating array of stolen Allomantic and Feruchemical abilities, making them nearly impossible to kill and overwhelmingly powerful in combat. They answer directly to the Lord Ruler and operate with absolute authority, hunting down skaa Mistings, rooting out rebellion, and enforcing orthodoxy within the obligator bureaucracy. Their eyeless faces and relentless pursuit make them objects of terror across the Final Empire. Despite their apparent loyalty, the Inquisitors harbour their own internal politics and ambitions - and their true nature and origins are more complex than even most of the nobility understand.

Kelsier's crew is a team of skilled Allomancers and specialists assembled by the Mistborn thief Kelsier to execute the most ambitious heist in the history of the Final Empire - the overthrow of the Lord Ruler himself. Each member brings a unique Allomantic ability or expertise: Breeze is a Soother who manipulates emotions, Ham is a Pewterarm with immense physical strength, Clubs is a Smoker who hides Allomantic signatures, Dockson handles logistics and finances, and Spook is a Tineye with supernaturally enhanced senses. Vin, a half-skaa street urchin who turns out to be Mistborn, joins the crew and becomes central to both the heist and the larger rebellion. OreSeur, a kandra bound by Contract, rounds out the team as a shapeshifting spy. What begins as an elaborate con becomes a genuine revolution, and the crew's bonds of loyalty and friendship are tested as the plan spirals far beyond what any of them originally imagined.

The skaa rebellion is the underground resistance movement fighting against the Lord Ruler's thousand-year reign over the Final Empire. The skaa - the oppressed lower class, kept in near-slavery by the nobility - have attempted uprisings before, but all have been crushed with overwhelming force. The rebellion operates in secret cells across the empire, coordinated by leaders like Yeden, who serves as its figurehead during the events of The Final Empire. Kelsier's plan to overthrow the Lord Ruler gives the rebellion its first real chance at success, combining Allomantic power, strategic deception, and the rallying symbol of the Survivor himself. The rebellion's army, trained by Ham and funded by the crew's stolen wealth, ultimately plays a decisive role in the fall of Luthadel - though the victory comes at a cost far higher than anyone anticipated.