It’s an incredibly powerful demon that’s destroyed over a dozen of Urokodaki’s students. The demon even gives Tanjiro a run for his money and nearly takes his life. Why didn’t Urokodaki defeat the Hand Demon?
Urokodaki didn’t defeat the Hand Demon because it was his job to capture it. 47 years ago, Urokodaki captures the Hand Demon and locks him inside the Wisteria-surrounded forest. The demon is meant to participate in the Final Selection exam as a threat for attendees.
Usually, demons are defeated in the exam after eating 2 or 3 attendees. The Hand Demon, however, has eaten over 50 and is incredibly large and powerful.
Urokodaki’s reason why he didn’t defeat the Hand Demon
Chapter #7 begins with Tanjiro squaring off against the Hand Demon. He’s only a few minutes into the Demon Slayer Corps Final Selection exam, but Tanjiro now must battle against a humongously powerful demon.
The Hand Demon refers to Tanjiro as “fox boy” because of the Warding Mask given by Urokodaki. Tanjiro does not wear his mask on his head. The demon asks what Meiji Emperor currently sits upon the throne.
Tanjiro answers that the current Imperial family is Taisho, and the Hand Demon bursts into anger. It scratches and gnaws at its own flesh, driven to insanity over the fact that dynasties have risen and fallen while he remains locked away within the Final Selection.
The Hand Demon damns Urokodaki in pure spite. Tanjiro begins to ask how the demon knows Urokodaki before being cut off by the explanation.
47 years ago, Urokodaki captured The Hand Demon. Back then, The Hand Demon explains, Urokodaki was just a regular Demon Slayer in the Edo Period of the Keio Era.
An immature Demon Slayer that Tanjiro protects speaks up. He says that the Demon Slayer Corps only captures weak demons to place in the exam, and they’re usually defeated after eating only 2 or 3 people.
The Hand Demon admits that its ridiculous size and strength comes from eating 50 different Final Selection attendees.
Amazingly, Zenitsu is able to pass the Final Selection. Inosuke, who doesn’t appear to be at the Final Selection, also passes.
So that’s the answer. Urokodaki didn’t defeat the Hand Demon because it was his job to capture it. 47 years ago, Urokodaki captures the Hand Demon and locks him in the Wisteria-surrounded forest of the Final Selection exam.