Background: Formerly known as Michikatsu Tsugikuni, he was the twin brother of the legendary demon slayer Yoriichi Tsugikuni. Consumed by intense jealousy and the fear of dying from the fatal curse of the Demon Slayer Mark, he willingly accepted Muzan's blood to become a demon and live forever to surpass his brother.  Appearance: A tall, intimidating swordsman with six eyes and long, spiky black-and-red hair. He wears a purple patterned kimono and wields a terrifying, flesh-and-bone-crafted katana that regenerates alongside him.  Abilities: As the strongest Upper Rank, he utilizes Moon Breathing—a devastating derivative of Sun Breathing that generates dozens of chaotic, crescent-shaped blade slashes. He possesses Transparent World vision, monstrous physical strength, and near-instantaneous regeneration.

Background: Born with iridescent rainbow eyes and pale blonde hair, Doma's parents viewed him as a divine child and made him the leader of the Eternal Paradise Cult. Emotionless and apathetic since childhood, he witnessed his parents' bloody deaths with total indifference before Muzan transformed him.  Appearance: A charismatic, perpetually smiling young man with rainbow-colored irises displaying his rank. He carries golden, lotus-engraved Japanese war fans into battle.  Abilities: He wields a powerful Cryokinetic Blood Demon Art, using his fans to conjure freezing mists, deadly ice lotuses, and colossal ice bodhisattva statues. Because he feels no genuine human emotion, he hides a chilling, predatory sadism behind a mask of friendly cheerfulness.

Background: Originally a human named Hakuji, he lived a tragic life in the slums, stealing to buy medicine for his sick father. After his father hanged himself and his new martial arts family was poisoned by rivals, a broken and vengeful Hakuji slaughtered 67 people bare-handed, drawing Muzan's attention.  Appearance: A muscular demon with pale skin entirely covered in dark blue, criminal-style tattoo lines. He has short pink hair, yellow-and-blue eyes, and fights entirely bare-handed.  Abilities: Akaza specializes in Destructive Kill (Hakai Satsu) martial arts, combining shockwave-generating hand-to-hand combat with a compass sensor technique that tracks an opponent's fighting spirit. He values strength above all else, refuses to consume women due to subconscious human memories, and boasts incredible adaptive regeneration.