Although simplistic, it was extremely terrifying because those Demons and Monsters were weak but highly infectious, and to survive, they must consume humans; after devouring a person, they would spread to even more people. In this manner, once the Demonic Qi took root, the world was essentially beyond cure.
As for Wang Yang, who was nothing but a mere mortal, there was only one way to cleanse the Demonic Qi, and that was through the aid of others. Reliant solely on his own strength, Wang Yang understood that it was utterly impossible.
After all, it was the dark Demonic Qi that had eroded many worlds. Wang Yang had already anticipated that it wouldn't be easy to deal with, and now he could only take one step at a time.
"My lord, even if we faced thousands of troops, we would not fear, but the creatures ahead are Demons and Ghosts!"