Can be used to refine Runestones, allowing them to regain additional attached abilities.

"A peculiar Sky Essence Stone that shimmers faintly with light, possessing mysterious energy. It can be used for Rune Refinement, making the Runestone's abilities more unique and even more powerful."

Usage: Open the Rune Refinement interface. Regardless of whether the refinement succeeds or fails, the Runestone will not disappear.