The Soul Devouring Restriction.
It was a lethal restriction that a high-ranking Nascent Soul cultivator of the Great Harmony Society had planted in Wei Yiling's and Feng Xishuang's divine souls.
Once triggered, it would annihilate their divine souls outright, killing them instantly before they could offer even a trace of resistance.
Clearly, that Nascent Soul cultivator had activated the Soul Devouring Restriction with the intent to kill them.
Fortunately, the Soul Devouring Restriction inside Feng Xishuang had been completely removed. Although Wei Yiling's had not been fully removed, only about one-sixth remained.
When the restrictions erupted, Feng Xishuang naturally escaped unscathed, while Wei Yiling suffered severe damage to her divine soul and fell unconscious, hovering on the brink of death. Fortunately, her life was not in immediate danger.
Fearing pursuit by the Great Harmony Society, Feng Xishuang had discarded both their Great Harmony Tokens and anything else that might reveal their whereabouts, then hidden somewhere secluded, not daring to return to Spirit Firmament City.
At the end of the jade slip, Feng Xishuang expressed her hope that Li Ping could find treasures in Spirit Firmament City that nourished the divine soul and deliver them to their hiding place to save Wei Yiling.
"The key to this must lie with those 'mortal cultists' Wei Yiling and Feng Xishuang killed."
Although Feng Xishuang had not stated it explicitly in the jade slip, Li Ping realized where the problem lay in an instant.
The Great Harmony Society's true target had been those so-called "mortal cultists." It could even be said that the preceding years of "slay demons and exterminate evil" missions had all been laying the groundwork for this.
The sole purpose of that series of missions had been to make Wei Yiling and Feng Xishuang lower their guard against the true targets.