Responding to Jing Chichyau's question, the phantom man, Leiling, replied like this:
"This is very simple. Although the Tuoshe Ancient Flame is the pill fire of the Tuoshe Ancient, after all, it lacks a true soul, leaving only a shred of lingering obsession upon it. Therefore, unlike Tuoshe Ancient, it cannot distinguish good people from evil ones on a soul level. It simply senses the aura of evil through instinct, then lunges forward to burn. If the soul is tainted, it burns the soul; if the body is tainted, it burns the body."
"As for your friends, although they look painful, obviously their souls are not very tainted. Instead, their bodies have been infected by an evil aura. The cultivator with the black blood mist behind him is the most severely infected."
Chapter 798