The benefit that Song Xiaodong mentioned was that when testing Sun Yiyi's energy vortex, he needed to guard his own True Qi. In this way, True Qi had an additional method of training.
Previously, he never even considered using this method to temper his True Qi. Now, after trying it a few times, Song Xiaodong had discovered that this actually made his True Qi more refined.
However, this left Sun Yiyi a bit frustrated. Every time, Song Xiaodong would just scratch the surface, arousing her desire but unable to proceed further, which was simply a kind of torment.
But knowing it was beneficial for Song Xiaodong, while the frustration in her body remained, her heart was joyous. Moreover, she slowly discovered that after each attempt, Song Xiaodong's endurance slightly increased.
