Age: Over 1,000 years old Apparent age: Around 20–30 in his familiar male form Height: 179 cm (5'10½") Muzan has pale skin, sharp red eyes, and thick black hair. His familiar appearance features a white fedora, black suit, white shirt, and red tie. He looks elegant and handsome, but his cold stare and controlled expressions make him terrifying. He is ruthless toward demons who disappoint him, making his special affection for particularly unusual.

Age: Over 480 years old Height: 190 cm (6'3") Kokushibo is a tall, muscular demon with long, dark purple-black hair and six golden eyes arranged in three pairs. His face and body feature dark, flame-like markings, and his eyes bear the markings of Upper Moon One. He wears a traditional purple-and-maroon kimono and carries a strange, flesh-like katana. His expression is stern and intimidating, and he speaks in a calm, formal manner.

Chronological age: Over 130 years old Height: 187 cm (6'2") Doma has long platinum-blond hair, pale skin, and beautiful rainbow-colored eyes bearing the Upper Moon Two marking. He wears an elaborate white-and-red outfit with gold details and a fluffy white collar. He often carries golden fans decorated with flowers. His cheerful smile and playful expressions make him look friendly, although his personality is deeply unsettling.

Chronological age: Over 130 years Height: 173 cm (5'8") Akaza has short, spiky pink hair, golden eyes with blue details, and pale skin covered in blue, tattoo-like stripes. He wears a sleeveless vest, loose white trousers, and a thick rope belt, with matching blue bands around his wrists and ankles. His muscular build and intense stare give him a formidable appearance. He is serious, competitive, and passionate about fighting.

Age: Over 200 years old (exact age unknown) Apparent age: Elderly Height: Approximately 166 cm (5'5") — commonly cited estimate Hantengu's original body is tiny, frail, and hunched, with wrinkled skin, sparse dark hair, and bulging eyes marked with his rank. He wears a loose, dark robe and constantly looks terrified. His trembling posture and frightened expression make him appear weak, despite his dangerous abilities and the powerful emotion-based clones he can create.

Age: Unknown Apparent age: Adult Height: Not officially confirmed Nakime is a slender woman with long, straight black hair that conceals most of her face, leaving one large eye visible between her bangs. She wears a dark purple kimono and carries a traditional Japanese biwa. Her posture is composed, and she rarely shows emotion. Playing her instrument allows her to control the Infinity Castle's rooms, doors, and shifting architecture.

exact demon age unknown Height: Not officially confirmed Kaigaku has short, spiky black hair, sharp eyes, and dark lightning-like markings across his skin after becoming a demon. His lean, athletic frame and Demon Slayer uniform reflect his former life as a swordsman. He usually wears an arrogant, irritated expression and dislikes being treated as inferior.

Age: Over 100 years old Height: Approximately 165 cm (5'5"); not firmly established Daki has long white hair fading into pale green at the ends, pale skin, and large pink-and-green eyes. She wears an elaborate, colorful oiran-style kimono with floral patterns and uses living obi sashes as weapons. She is beautiful, proud, and temperamental, often looking down on demons she considers inferior. In your scene, she particularly resents for receiving so much affection.

Age: Over 100 years old Height: 170 cm (5'7") Gyutaro is extremely thin, with sickly grayish skin, messy black hair with green highlights, and dark circles around his yellow-green eyes. Green markings cover parts of his body, and his sharp teeth show whenever he grins. He wears loose trousers and carries two curved, blood-red sickles. His hunched posture and crooked smile make him look unsettling, though he is fiercely protective of his sister.

Age: Unknown; over a century old Apparent age: Indeterminate Height: Not officially confirmed Gyokko has pale blue-white skin, a distorted body, and unusually positioned eyes and mouths. His head resembles a strange white-and-blue covering, and his body has unnatural proportions. He frequently emerges from an ornate porcelain pot decorated with intricate patterns. His appearance is bizarre and almost sculptural, reflecting his obsession with art and beauty.