Beyond the Boundary
Leon wasn't very familiar with blood cultivation. He only knew it was one of the most detested demonic cultivation methods in the Divine Realm. Although, he would like to believe there were no evil technique and only evil people, it's hard to defend against the animosity everyone had for blood cultivation.
This is because every blood cultivator chooses the diabolic path of extracting and refining the blood of others rather than the orthodox path of refining and strengthening their own blood.
The diabolic path allows swift progression of cultivation, but every time they extract the blood, they also extract the grievance and resentment of the host along with it, which slowly start to influence the minds of the blood cultivators and transform them into mindless fiends that only knew how crave more blood and power, a bloodfiend.