Quyang County, Yunmeng Mountain.
The Yunmeng Mountain that Xu Qing sees today is vastly different from the one he saw more than a decade ago.
Back then, though Yunmeng Mountain had poisonous miasma, it did not have thick mist. But now, the mountain is shrouded in dense fog, making it impossible to see anyone within five steps.
Lord Yuan once told Xu Qing that in the upper realm, there are four treasures: wind, mist, cloud, and qi, also known as the Four Mothers.
A thousand years ago, when Lord Yuan was punished to guard the White Cloud Cave in the lower realm, the Celestial Emperor, in consideration of the Nine Heavens Profound Lady, lent him one of the Four Mother's treasures: the Mist Veil.
The Mist Veil resembles a curtain, and when unfolded, steaming mist gushes out. If fully expanded, it spreads for a hundred miles; even an Immortal would find it difficult to discern the mysteries within.