One-Punch Man. Vol. 13. Techno Knight. Unknown Power

Grade S heroes, with the support of their Association comrades, continue to fight against monsters. They freed the capricious one from captivity, but it turned out that another child was lost underground. While the rescuers were deciding who would go back for the boy, Saitama wandered through the lair in search of the source of the noise and, unknowingly, crushed the Lord of All Monsters - the Serpent King! Meanwhile, deep in the dungeon, Garo regained consciousness, declaring a hunt on the heroes... The book includes chapters 119–131, as well as bonuses.