Because the Profound Nether Yin Fire Palm carries a kind of half-yin half-yang Yin Fire Force, once hit by it, the Yin Fire enters the body and burns the opponent's Primordial Energy, quickly causing the victim to lose all their energy and unable to use any Secret Skills.
Moreover, the Yin Fire Force would cause a person's yin and yang to become unbalanced. Anyone struck by the Profound Nether Yin Fire Palm would feel alternatively cold and hot, as if suffering from both heat and cold sickness simultaneously. On top of having a high fever, they would also become extremely weak.
The Profound Nether Yin Fire Palm can be said to be an extremely malicious Secret Skill, even more effective than many Unparalleled Secret Skills.
However, it has a fatal flaw: a first-level Profound Nether Yin Fire Palm consumes 21 points of Primordial Energy each time it's used.
