Steelrunner

A Feruchemist who stores physical speed in a steel metalmind — moving slowly for a time to fill it, then drawing on the reserve later to move with speed-bubble-like swiftness without the warning of a bubble. Uncommon even as Feruchemists go. Wax and Wayne judge that one of them killed Winsting Innate's saferoom guards too quickly for them to turn around. MB2:SoS:Ch 4