Nam-gyu is shown to be a more violent, cruel and sadistic than even Thanos is. While Thanos treats his teammates with respect and is even upset by Gyeong-su's death, Nam-gyu bullies both Se-mi and Min-su frequently, to the point where even Thanos calls him out for it.

While as not nearly as unhinged as Thanos, Nam-gyu is still somewhat mentally disturbed. Like Thanos, he doesn’t care about using other people to his advantage and sees them as disposable. He also shares Thanos' vengeful nature