"Why, do you feel this harvest is not yet grand enough?" Mother Zhou asked, her smile carrying a hint of irony and seven parts anticipation.
Zhou Tieyi was momentarily incoherent. "I, this, it's not that..."
Mother Zhou laughed heartily before continuing with a serious tone: "You have realized it yourself. As one’s cultivation deepens, it becomes increasingly difficult for powerful beings to conceive offspring. This is a law of the Heavenly Dao. For instance, pure-blooded dragons and phoenixes of the Third Rank require several hundred years to have any chance of success. In fact, most pure-blooded dragons and phoenixes are not born of physical union, but are formed from the essence of heaven, earth, mountains, and rivers. For you and Miaoyu to conceive, the difficulty is even greater than that of the dragons and phoenixes. Unless the fated moment of heaven and earth arrives, it is absolutely impossible."
Chapter 502