"Body Essence?"
This was the first time he had extracted something called Body Essence.
From what he read from his system' notes, Body Essence could be obtained from Magical Beasts and humans, especially cultivators who trained their bodies using body cultivation techniques.
Qin Yi also has several body cultivation techniques in the storage system but is he unwilling to practice them. That's mainly because practicing the body cultivation technique has a strenuous training process.
Every day, you need to temper your body in brutal ways, such as pulling large boulders, training under the pressure of waterfalls, doing marathons three times a day, etc.
Although the results are satisfactory, the process is very tiring and troublesome.
Radically, people need to think twice before deciding to practice body cultivation techniques because it is very time-consuming as the progress is so slow that it can hinder cultivation.