In the cave.
Fang Xing caressed the pitch-black Jade Scroll in his hand that was named 'Corpse Refinement Secret Scripture.'
After reading it through, he had gained a rough understanding of the Demon Path's art of corpse refining.
"It seems that Stone Daoist wasn't very adept at the Way of Corpse Refining; the 'Heavenly Sha Blood Corpse' he chose only had the advantages of being made from simple materials, easy to control, and relatively quick to create... Compared to the truly powerful corpse refinings that were said to be almost Fourth Rank in strength, capable of rivaling a Nascent Soul Cultivator, it still falls quite short..."
Of course, those few powerful corpse refinings not only required extremely difficult to obtain materials for their rituals, they also had many special requirements, nearly impossible to fulfill, basically huge pitfalls.
For example, the 'Dutian Demon Corpse' required a complete corpse of a Fourth Rank Body Cultivator as the raw material.