In ancient Chinese myths and legends, the three realms referred to the Heaven Realm, the Earth Realm, and the Human Realm. Among them, the Heaven Realm was believed to be the place where immortals lived, while the Earth Realm and the Human Realm were believed to be the places where mortals lived. There was no clear answer to the question of who had the greatest magic power in the three worlds. Different stories and legends might give different answers. Some legends might mention that the immortals in the Heaven Realm had stronger magic power, while others might mention that the mortals in the Earth Realm had stronger magic power. For example, in Journey to the West, Sun Wukong was defeated by the immortals in the Heaven Realm when he caused trouble in the Heavenly Palace. Later, under the leadership of Tang Sanzang, Sun Wukong and the others went to the Western Paradise to obtain the scriptures. During this process, Sun Wukong kept learning Buddhism to improve his mana. Therefore, in this story, Sun Wukong was regarded as the immortal with the greatest magical power. Different stories and legends might give different answers. The specific situation needed to be analyzed according to the specific legends.