An optimal supplementary medicine pill for breaking the bottleneck to the Spatial Tempering stage.
In the entire world, only the Black Phoenix Clan can refine these pills by using their personal flames. Even pill refinement masters aren’t able to duplicate them.
Refining these pills requires them to absorb the life flames of a Black Phoenix in addition to other mysterious materials. That is to say, even the Black Phoenix Clan can’t produce many of them. A clan member must be at Deity Transformation-stage or above, and even then, they can only refine a single pill every thousand years.
With high-grade Black Phoenix cultivators rarely seen, the Black Flame Pills are as previous as one might imagine. The pills are prized among humans and demons.