In fact, both the Xia Clan and the Ning Clan have studied Medical Poison Skill, but the Ning Clan's research is more thorough, and the Wu Clan is actually a branch of the Ning Clan. However, Ning Shiqi wouldn't say this in front of Xia Wu.
"The poison she was afflicted with is called the Disturbing Emotional Gu. It is one of the least conspicuous types of Gu Worms but can easily manipulate a person's emotions. This Gu Worm is as fine as mycelium and has almost no presence. Even once inside a person's body, they wouldn't feel anything. Yet it burrows into the nerves, gradually affecting and controlling a person's emotions. Over time, they become completely controlled, hardly aware of what they are doing or have done, and become irritable and quick to anger. Even if they realize something is wrong, it's difficult to detect."
Or rather, it cannot be detected at all.
