Most cultivators didn't have to make it so complicated when they tempered their bones after completing nascent tempering. All they would need to do was draw medicinal energy into their bones.
That was the normal tempering method. But Luo Cheng wanted them to undergo complete tempering. They could not be missing out on even a single bone.
So he needed to refine this Bone Connecting Pill. It would allow them to create a full, one-time connection between every bone in their bodies.
After forming that connection, then they could undergo bone tempering.
This was like the process of building a complicated canal system. Only once you confirmed the routes would you begin building them. Then everything would flow naturally.
However, this was a fifth grade alchemy pill, and it required a main alchemy ingredient with a very powerful energy. So Luo Cheng could only endure the pain and use a Dragon Fruit.
