Shin, an elite cleaner serving crime lord En, wields lethal magic that slices targets without instant death, leaving severed limbs to decay unless reattached. Born in the dystopian city of Hole to a human father and magic-user mother, he concealed his hybrid lineage until anti-magic vigilantes murdered his father. This sparked a vengeful crusade against the militia, driving him into hiding. To harness dormant powers, Shin performed self-surgery with medical tools, activating smoke veins in his arms that left permanent scars and stitches. His path crossed Noi’s during a food theft from En’s domain. Their first clash saw Noi heal his wounds to ensure a fair duel, which Shin concluded by overpowering her and escaping—laying the foundation for their eventual partnership. Sporting short blonde hair and a muscular frame, Shin dons a reversible heart-shaped mask: casual wear features it backward, while combat orientation amplifies his smoke magic. Corrective glasses address post-adolescent vision decline. His wardrobe oscillates between tailored suits and athletic wear, prioritizing function. A tactical observer who savors combat’s adrenaline, Shin avoids gratuitous violence but visibly thrives in arduous fights. He tempers Noi’s impulsivity with calculated strategies, though begrudgingly tolerates her affectionate antics. Trauma from Hole ingrained habits like wolfing down meals and sleeping with one eye open. Notable missions involve pursuing Kaiman, a lizard-headed magic-user immune to standard attacks. Shin’s decapitation of Kaiman—only to witness his regeneration—unraveled investigations into cursed dolls and disembodied heads tied to Kaiman’s affliction. The Blue Night assault nearly claimed Shin’s life when assailants Baku and Yaku struck, prompting Noi to sacrifice her devilhood chance to heal him, cementing their loyalty. Beyond smoke magic that ignores durability—halting projectiles and dismembering foes—Shin excels with hammers and hand-to-hand combat. His enhanced pain tolerance lets him endure slit throats and organ damage. Prolonged exposure to Hole’s corrosive rain drains his magic, though hybrid physiology prevents fatal consequences. While a trusted Enforcer for the En syndicate, Shin privately scoffs at En’s eccentric ventures. His past includes raising a creature named Gura-Gura and a preference for minimalist style. The kanji for “heart” inspires his name, echoed in his mask’s shape and a smoke portal labeled “EL CORAZON.”