I need your help. On the island where Xie Xun, Zhang Wuji and Zhou Zhiruo stranded, Zhang Wuji tried to use the 9yang energy to force the poison out of Zhou Zhiruo´s body. But when trying this, he noticed that inside her body there was a yin energy.
See chapter 31:
"The next day Zhang Wuji used the Jiu Yang Shen Gong to help Zhou Zhiruo expel the poison. At first they made a good progress; perhaps because she did not eat too much, her level of poisoning was not as severe as Xie Xun. However, toward the seventh day, suddenly he felt a resistance, which was ‘yin’ [negative/female] and cold in nature, coming from her body, fighting his Jiu Yang energy. Although Zhou Zhiruo strived to control this resistance, it was difficult for the Jiu Yang energy to enter her body. In his astonishment Zhang Wuji went to consult Xie Xun.
Xie Xun pondered for half a day before saying, “I don’t know for sure, but most likely it was because her Emei Pai’s masters were always women, the internal energy they train is ‘yin rou’ [negative/female, and soft/flexible] in nature.”
Zhang Wuji nodded his agreement. Luckily Zhou Zhiruo’s internal energy level was far below his, so that he was able to suppress the resisting ‘yin’ energy in her body; but by doing this he was required to use up a lot more energy than when he was helping Xie Xun. Zhang Wuji secretly felt that although at this moment her ‘yin’ energy was still weak, but her achievement in the future would not be a small matter.
“Zhiruo,” he praised, “Zunshi [revered master] Miejue Shitai was truly an expert of her generation. The internal energy cultivation method she passed on to you is extremely profound; I
can feel it even now. If you train diligently, your energy level may run neck to neck with my Jiu Yang Shen Gong; you may even surpass me.”
So, my question is where is the 9yin energy coming from. Emei´s energy is based on 9yang and Guo Xiang never learned the 9yin manual.
See chapter 30:
“Laoye Zi,” Zhou Zhiruo suddenly asked, “I heard a hundred years ago in the Wulin world there exist some experts who were proficient in the Jiu Yin Zhen Jing [Nine Yin Manual]; is that true?” On MountWudang, Zhang Wuji had heard his Da Shifu [great master] mentioned the name Nine Yin Manual; so he knew that the founder of the Emei Pai, Guo Xiang Nuxia’s [heroine] father, Guo Jing, and the ‘Shen Diao Daxia’ [Divine Eagle Great Hero] Yang Guo, both had mastered the martial arts from the Nine Yin Manual. But the skill contained in the Manual was very difficult; so that although Guo Xiang was Guo Jing’s own daughter, she still had not learned it. Listening to Zhou Zhiruo’s question he thought, “Could it be that the Emei Pai’s founder has handed down parts of the skill contained in the Nine Yin Manual?"
So, in my opinion Jin Yong wanted to give us a hint with the sentence of Wuji "If you train diligently, your energy level may run neck to neck with my Jiu Yang Shen Gong; you may even surpass me" that
Zhou Zhirou already started to learn the 9yin manual. But after she got the Dragon Sabre and the Heaven Sword she didnt have time to go to Peach Blossom Island (3rd edition) to take the 9yin manual. The discussion about the yin energy in Zhou Zhiruo´s body make only sense with the first or second edition of HSDS where the 9yin manual was hidden in the Heavenly Sword.
So, how did Jin Yong explain this in the 3rd edition?