A parchment formula for countering the Soul-Eroding Plague, containing blurred herbal diagrams and twisted runes. Yun Gu determined the approach was correct—using extremely yang, fiercely potent medicines to counter the cold gu venom—but the proportions were wrong and several crucial ingredients were missing, especially those that temper violent drugs and protect the heart meridian. Medicine alone could not break the summoning rune.
