C75 Fickleness of heart

When I heard Xia Mingyuan say the Great Charm of Mercy, I subconsciously thought it was some sort of buddhist spell, but wasn't this spell supposed to be used to save people? How did it become a Killing technique?

"What is the Great Charm of Mercy?"

Xia Mingyuan looked at Zhou Xi Xi and Captain Long, and decided to speak the truth. With the current situation