Prior to the beginning of the manga, Legato was a nameless slave. While imprisoned, he slowly developed his power by weaving metal threads into his brain, allowing him to take control of other bodies. Before he could fully develop his power, he was discovered, wounded, and raped. However, Knives happened to pass by and destroy the city, with Legato being the only survivor thanks to the power of his threads. Legato immediately becomes infatuated with Knives and swears eternal loyalty, showing his willingness to allow Knives to kill him. Knives takes the boy in as a tool, and presumably names him. Later, Legato and Dr. Conrad, a friend of Knives, found July City in ruins and Knives heavily wounded. Legato sees Vash in the distance, and realizes Vash is the cause of Knives's serious injury, but Conrad convinces Legato to help tend to the wounded Knives instead of chasing after Vash. Seeing Knives in such a state traumatizes Legato, who swears revenge on Vash, eventually leading Legato to plan a killing game to torment and eventually kill Vash.