Qin Liuxi once said she would use the Taoist Sect's secret techniques to transmit sound and inform all the cultivators in the world. Chengyangzi had thought all cultivators would be notified, not knowing that her transmission over thousands of miles was selectively received, requiring a cultivation level of at least the fifth layer of Qi Cultivation to hear it during meditation.
All cultivators need to cultivate, and the daily practice of the small and grand circulation in Taoism is also a kind of cultivation. Thus, this secret technique is transmitted during their meditation. As for why only those above the fifth layer of Qi Cultivation, it is to prevent them from being frightened suddenly and losing composure, thereby disturbing their True Qi and leading to deviation.
Qin Liuxi is calling people, not harming them; those beyond the fifth layer of Qi Cultivation are capable of handling this transmission.
