Qin Mu took down another hexagon-shaped crystal that was almost as tall as him. He stood behind the crystal and looked through it. The world appeared different due to the crystal's refraction.

"Looking through the crystal as an eye is different from an actual eyeball. However, I believe that shouldn't be the crystal's only use."

Qin Mu touched the heart of his own brows, which had a small bump.

During the calamity of the Primordial Realm, he dug out his third eye and threw it into Youdu. Ever since the wound at the heart of his brows had healed, there had been a small meaty bump.

"In the past, my third eye was used to connect with Youdu, to execute the divine arts of the Great Dao of Youdu. These prehistoric giants embedded the crystals into the heart of their brows… What divine arts were they trying to execute?"

He didn't have an answer even after thinking for quite some time. After pondering for a time, he went to the center of the sacrificial altar and looked at the body of li