There were many evil martial arts secret manuals in Jin Yong's Wuxia. It was difficult to determine which one was the most harmful because each secret manual had its own unique characteristics and the impact on the user was also different. However, the following were the martial arts manuals that were generally considered the most evil in Jin Yong's novels: [1. Nine Yang Scripture: This secret manual can greatly increase the user's internal strength. However, once it is mastered, it will cause great damage to the body, resulting in continuous internal injuries and even death.] [2. Muscle-bone Strengthening Scripture: This secret manual can greatly improve the user's physical fitness, but it will also cause the user to have too much psychological pressure and may even lead to depression and other psychological problems.] 3. Sunflower Manual: This secret manual can allow the user's martial arts to advance by leaps and bounds, but it will also cause the user's psychological distortion to become cruel and heartless, and may even cause self-harm. [4. Legend of the Condor Heroes: This secret manual can allow the user to become a Condor Hero, but it can also cause the user to lose his humanity, become cold and heartless, and even forget his original heart.] Therefore, which one was the most harmful still needed to be analyzed according to the specific situation of the user.