"Bone strengthening!"
Chen Jie questioned in confusion, but upon hearing this, Doctor Bai gently nodded and said, "Yes, exactly, bone strengthening."
"Ming Jin hones the skin and flesh, Dark Force strengthens the sinews and bones. After the Refining Body Realm, one needs to exercise the twelve major tendons in the body, making the long tendons as supple as supporting willows, this is the training goal of the next Realm, also known as the Liu Jin Realm."
"After the Liu Jin Realm, one begins to temper all the bones in the body. When the bones become as refined as steel, one has reached the fourth Realm, the Iron Bone Realm."
"And the Elixir that aids in transitioning from the Liu Jin Realm to the Iron Bone Realm is the Bone Strengthening Pill, similar in function to the Skin Tempering Soup and Blood Replenishing Soup."