"I see…" Hearing that explanation, Zhang Xuan came to a realization.
No wonder!
He had been wondering why the Skyleaf King would choose to send his severed Primordial Spirit after them when it would have been safer for him to do it personally, especially for something as important as the map. It turned out that it was not that he did not want to do so, but he could not! Trapped in the depths of the ancient domain, he had no choice but to leave this job to his severed Primordial Spirit.
A thought came to Zhang Xuan's mind. Having reached the Leaving Aperture realm, the Skyleaf King's Primordial Spirit is capable of existing for extended periods of time outside of his body. However, that is not the case for the severed Primordial Spirit. Inevitably, it is weaker and unstabler than a complete Primordial Spirit, so it is incapable of surviving independently for too long a period of time. Perhaps, the severed Primordial Spirit was hiding in the Earthleaf King's body back then.
