C380 The Other Use of Yin Energy

"Could it be that the Yin Strength can only be refined by the Nether Spell?" Lee Lin muttered, as if he was asking himself and the Prison Ring. At this moment, the secret of the Yin Strength seemed to have been grasped by him.

He impatiently looked at the few remaining Yin Strength in front of him. In order to verify his thoughts