It turns out that the one trapped in the Kunlun Mountains all along wasn't Dragon Soul Liaoyuan, the Agent of the Fire God Zhurong, but rather the Tier 2 ghost general, the Headless Warlord Bra!

Dragon Soul Liaoyuan stayed in the Kunlun Mountains solely to protect the Headless Warlord, or rather, to protect Dragon Soul Xingtian, who had signed a symbiosis contract with the Headless Warlord!

The Headless Warlord was affected by the ghost formation and couldn't leave the Kunlun Mountains.

And Dragon Soul Liaoyuan was also bound by the Headless Warlord, forced to remain in the Kunlun Mountains.