Can't afford to change

"Mr.Pembroke is truly a god! He can kill snake demons and refine elixirs. Unfortunately... these elixirs cannot cure the old man's hidden disease. If there were an extremely yang and strong elixir, I'm afraid the old man would be saved!"
Li Xinran was slightly startled, "Master Hong, what do you mean?"
"Even if Mr.Pembroke removes the evil spirit from the ghost grass as much as possible, the raw material is still a yin thing after all, so the nature of this pill cannot be changed." Old Hong...