The koloss are massive, brutish creatures created through Hemalurgy - the dark art of stealing attributes via metal spikes driven through the body. Each koloss is made from multiple human beings, their stolen strength fused into a single being of terrifying physical power but limited intelligence. Koloss grow continuously throughout their lives, their blue skin stretching and tearing as their bodies expand beyond what the skin can contain. They are used by the Lord Ruler as shock troops and instruments of terror, deployed to crush rebellions and enforce obedience across the Final Empire. Without a strong Allomantic or Hemalurgic controller, koloss are nearly mindless in their violence - but under the right command, they can be directed with devastating precision.