Void Star Metal?

"Wh-what is that?" Lin Mu muttered in amazement.

The entire process that had happened in front of him was nothing short of world changing to him. This was the first time he was witnessing another aspect of cultivators which was the refinement of materials. The process was obviously very complex, and Lin Mu could not even begin to imagine how much effort it would take to learn it all.

It was obvious that the experience the Old man had was nothing short of world shaking. If Lin Mu knew that what he was witnessing was desired by countless other cultivators, he would be astounded. There would be tens of thousands of cultivators who would start a war just to have the chance of witnessing this and learning from this.