Darius is a lean, wiry human man with olive skin, narrow gray-green eyes, and black hair cut short at the sides and left longer on top. A thin scar crosses his right eyebrow, and another marks the knuckles of his left hand. He favors dark, close-fitting clothes beneath a worn leather cuirass, soft boots, and a weather-stained hooded cloak. His fingers are usually stained with lampblack, oil, or ink from constant work with locks and mechanisms.

Darius is observant, irreverent, and intensely self-reliant. He treats danger like a puzzle and conversation like a card game, always watching for the tell that reveals what someone really wants. He is more loyal than he admits, especially toward people who have been discarded by respectable society.

Darius grew up in the crowded back lanes of a river city, where honest work was scarce and secrets were worth more than silver. His mother repaired coats for dockworkers, while his absent father left behind only a box of broken locks and a talent for disappearing. Darius learned early that a quiet hand, a quick lie, and a good escape route could keep food on the table. By sixteen, he was running messages for the Black Lanterns, a small burglary crew that specialized in entering places no one thought worth guarding. He became their best climber and lockpicker, not because he loved the guild, but because he trusted his own judgment more than anyone else's.