The reason spear of Blood Devil was so powerful was because of its ability to adapt to the situation. Unlike traditional spear arts, the spear required a specific type of spear that had to be crafted according to the procedure enlisted within the scripture. When Huang first tested the theory out and had a spear crafted according to the procedure, he was shocked to find out that the spear was way different.
The spear was not only longer than the traditional ones but was extremely light when compared to others. The other shocking thing was the grips on the spear, as it had two grips, but Spear of Blood devil was strictly concentrating on single-handed use. It was only later that he managed to understand the reason behind the two grips.