The Executioner centers on Gangyu, a celebrated hero whose steadfast belief in mercy is shattered when a catastrophic prison break unleashes dangerous criminals back into the world. Haunted by personal loss and frustrated by a justice system that fails to protect the innocent, he accepts a radical new role: becoming the prison’s official executioner. From the moment he steps into Ruculus’s shadowy halls, every choice forces him to question whether true justice lies in redemption or in finality.

At the heart of the story is Gangyu himself—once a paragon of virtue, now driven by a fierce determination to keep others safe at any cost. He works under the watchful eye of the Ruculus warden, who grants him extraordinary authority, and alongside a diverse cast of inmates and guards whose own histories and motives collide with his mission. Together, they inhabit a stark institution that tests the limits of law, morality, and the meaning of heroism.