This world is not only as the public knows it; there is an underworld that ordinary people don't encounter. Government agents handle troubles in the shadows, while corporate assassins privately deal with issues. Assassins, mercenaries, arms dealers, and spies exist, along with a dark web that ties this world together, and tycoons who attempt to control everything with money. Gao Yi entered the underworld, unbeatable in close combat, carving out his own domain. But there are guns in this world. Beyond seven steps (close combats), guns are faster. Within seven steps, guns are both accurate and quick. Only within three steps does Gao Yi's punch become faster. Unable to beat them, he chose to join them, aiming to rule them all. To rule everything, become the king of killers in the eyes of mercenaries, the king of spies in the eyes of assassins, the king of killers in the eyes of spies, and the king of intelligence in the eyes of arms dealers. Until he is crowned king by the entire underworld, Gao Yi is the ultimate firepower.