Originally, Li Qinghai thought that his Emperor Body could already accommodate a second imperial technique.
But after trying, he realized that while his Emperor Body indeed had a high probability of accommodating a second imperial technique, it couldn't accommodate one of the top ten imperial techniques.
Even though the Great Yin-Yang Technique was ranked tenth among the top ten imperial techniques, it was not easy to cultivate.
According to the Great Emperor Yaofeng, he needed to go to the second segment of the ancient river of time to find the Crystal of Time to strengthen his Emperor Body.