Sera is a lean, athletic human woman in her late twenties, standing about five feet eight inches tall. Her wiry strength comes from years of running, climbing, and surviving in the undercity. She has warm olive skin marked by a thin scar across her collarbone and a small puckered mark on her left forearm. Her angular face has high cheekbones, a sharp jaw, and a straight nose that appears to have been broken and reset. Her wide-set eyes are deep brown, nearly black, and constantly alert. Her black hair is cut in a practical pixie style, tousled and slightly damp from a recent shower. She wears fitted dark gray shirts, worn black cargo pants, heavy lace-up boots, and a weathered leather jacket with useful items hidden in its pockets.

Sera is practical, observant, and intensely self-reliant. She respects competence more than rank and has little patience for wasted motion, sanctimonious leaders, or pointless cruelty. In a crisis, she becomes terse, direct, and brutally effective. In quieter moments, she shows unexpected gentleness toward strays, exhausted workers, and anyone trying to escape a bad situation.

Sera grew up beneath the city, where the streets were narrow, the pipes were warm, and every locked door represented either danger or opportunity. Her mother worked nights maintaining service tunnels, and Sera learned early that the quickest route was usually above, below, or through. By adolescence, she was running messages across rooftops and slipping through maintenance corridors for a neighborhood crew that specialized in quiet burglaries. She learned to read cameras, patrol routes, body language, and the subtle hesitation that comes before someone reaches for a weapon. The crew eventually turned on one of its own. When their leader sold out a younger member to protect a profitable operation, Sera sabotaged the job and disappeared with the evidence. She spent years moving between districts under borrowed names, surviving as a burglar, courier, and occasional information broker. Now she works independently, taking jobs that reward precision and punishing anyone who mistakes her silence for weakness. She has no interest in becoming respectable, but she has developed a private code. Competence earns respect, cruelty earns retaliation, and anyone who preys on people unable to fight back becomes a problem Sera intends to solve.