Sethis is a lean, broad-shouldered tiefling with deep umber-red skin, swept-back black horns, and pale amber eyes. His tail is long and expressive, usually curled around one ankle when he is standing still. He wears a weathered leather jerkin beneath a deliberately respectable charcoal coat, with a faded blue silk scarf wrapped twice around his neck. The scarf is worn thin at the left edge from years of rubbing it between his fingers while thinking. His hands are the most immediately distinctive thing about him, with strong knuckles, ink-stained fingertips, and polished calluses along the thumb and forefinger from lockpicks, cards, and forgery tools. A small brass locket shaped like a closed fan hangs at his throat, its hinge worn bright from constant handling.

Sethis is observant, dryly courteous, and more comfortable performing sincerity than feeling it. He notices small practical details, remembers people's preferred names, and gives compliments that are so precise they can sound like veiled insults. Beneath his practiced composure is a protective streak he tries to disguise as professional interest.

Sethis was raised in the crowded lower wards of a river port, where tiefling families learned early that a polished name could open doors that horns and honest poverty could not. His mother taught him to read ledgers, recognize quality paper, and keep his temper while merchants lied to his face. His first successful deception was not a confidence trick but a correction to a shipping manifest, changing one line so a starving family received a crate of grain instead of a crate of lamp oil. The owner blamed a clerk, and Sethis discovered that truth and fraud often differed only in who had the better handwriting. As he grew older, Sethis became a traveling forger and confidence man, selling harmless identities to people who needed a second chance and less harmless ones to people who deserved to lose money. He learned to use a rapier as naturally as a pen, striking only when escape, persuasion, and misdirection had failed. His latest identity belonged to a dead minor official, and the disguise worked perfectly until the official's former patron recognized the brass fan locket Sethis carried. The locket once belonged to his mother, who disappeared after exposing a network of nobles using forged debt records to seize whole neighborhoods. Sethis now adventures to find her trail, collect evidence against the conspirators, and decide whether he wants justice, revenge, or simply the freedom to stop running.