"Soul Essence, you need a large amount of it. You should try your best to control the power, so I can bring you back to the military. They have enough Soul Essence to prevent your soul from breaking down due to the aftereffects. The Demon Element is indeed a demon. It's like signing a contract with a demon, which can grant you its power, before coming back to claim your soul," Zhan Kong said to Mo Fan.
Although Mo Fan possessed four Elements, the more power he used, the stronger the aftereffects he would have to bear.
The only way to protect his soul was by using a large amount of Soul Essence!
Soul Essence was useful in strengthening a Magician's soul. If the demon that had granted Mo Fan the power was drawing his soul away, he could neutralize it by using a sufficient amount of Soul Essence.