Shang-Chi’s fighting abilities were honed by his father’s insistence, as part of grooming him to be one of his top assassins, not foreseeing that he will rebel against his wishes. Perhaps after Shang-Chi refused to follow his father’s orders where he doesn’t have to beat people up so he decided to leave and lead his own life only to be roped back in after an encounter with the Ten Rings. the terrorist organization that goes by the 10 Rings, which is led by none other than Shang-Chi’s father, Wenwu, a.k.a. The Mandarin (recollect memories of Ironman movies), eventually comes calling.