It has been proven that talents among humans are indeed of varying degrees, and this applies to mortals living amidst the smoke of the world as well.
Out of the seven people that Wei Yuan had high hopes for, only two Heavenly Base Cultivators gained some insight, advancing from Dao Foundation to Immortal Foundation, while the other five attained nothing.
These Dao Foundation Cultivators constantly needed to consume Dao Power to resist the icy invasion of the You Han Realm, and as such, two Human Rank individuals soon could not endure and had to return to the mundane world.
The two Hall Masters, however, were very composed, and it seemed that spending an entire day in the You Han Realm posed no problem. Wei Yuan let them move freely in the small valley, suggesting they collect more samples to take back to the Heart Image World for research, while he repeatedly tested the spell of that doorway.