Black Heaven Book.
A martial art imbued with profound fantasy, not operating within the Extraordinary Meridians and other Visible Meridians, but rather affecting the body's Hidden Meridians. Said Hidden Meridians, if the Extraordinary Meridians and Visible Meridians are rivers on land, then the Hidden Meridians are subterranean rivers flowing beneath. There are thirty-one Hidden Meridians in total, conforming to the numbers of heaven, named after the Three Constellations and Twenty-Eight Stars.
Ordinarily, one practices martial arts from the Refining Essence and Transforming Qi phase, to Refining Qi to God, and then to Refining Spirit to Emptiness; however, the Black Heaven Book skips the Jing Qi Two Gates phase and starts directly from Refining God. Nevertheless, because it skips both Refining Essence and Transforming Qi and Refining Qi to God, its cultivation necessitates aid from another's Inner Strength.