The benefit of a walking corpse lies in its lack of pain or awareness, with no feelings at all, it merely hunts prey based on instinct. If not controlled, it would be a "perpetual motion machine," never stopping. Although Chang Wutian and the others are cultivators, they are ultimately flesh and blood and cannot withstand the torment of the "Drilling Armor Corpse". They can only abandon their plans and escape to the cave.
The "Drilling Armor Corpse" naturally wouldn't let them off, chasing swiftly and slashing aimlessly with its large diamond-embedded hands, like a meat grinder. In no time, it slaughtered several cultivators, sparing only Chang Wutian and his son.
Seeing the "Drilling Armor Corpse" turn its attention to him and his son, Chang Wutian, filled with righteous indignation, tricked it with his son into the stone chamber where Elder Chang Wei had perished.
