East courtyard.
After Yang Kai and Gong Mingyuan left, Jiang Ning also returned to continue his training.
As for the Dragon and Tiger Strength Pill, he solemnly placed it in his own room.
His Refining Skin had not yet achieved great success, had not reached the level of toughness of copper, and hence wasn't suitable to refine this Dragon and Tiger Strength Pill.
The medicinal power of this pill was too strong, formed under the forging power of the dragon and tiger.
It would cause his muscles to undergo a huge transformation in a short period of time.
Such a sudden fierce transformation; without sufficient toughness in the skin and membranes, could cause some kind of irreversible injury.
His body might even split open.
This sort of thing had happened before.
Thus there was the step of first refining the skin, then refining the power.
All these were experiences summarily concluded by the predecessors step by step.