Xu Wuyi sat down cross-legged, sinking his consciousness into his dantian.
The dark golden heart fire burned silently, steady and restrained.
Following the method, Xu Wuyi began guiding his mental power into the heart fire for tempering.
Unlike before, this time he could clearly feel that the interaction between his mental power and the heart fire had become more "in sync."
That thread of mental power he had separated out still brought searing pain when it entered the heart fire, but amid the pain, Xu Wuyi could more clearly sense the process of impurities being removed, as well as every subtle change as his mental power was hammered and condensed.
He even began trying to fuse his understanding of "mountains" and "burning," along with the piercing sharpness in his spear technique, into it while his mental power was tempered by the heart fire.
This was no simple visualization. Using his spirit as a medium, he fused his martial will with the heart fire for a deeper level of tempering.
It did not go smoothly at first.
The integration of martial will made the structure of his mental power more complex, and the difficulty of tempering it rose sharply.
Several times, the threads of mental power could not endure such composite tempering and dispersed within the heart fire, bringing even more intense backlash pain than usual.
But Xu Wuyi did not give up.
He adjusted his approach, gradually feeling out the right balance and rhythm.
Whenever he failed, he started again. Whenever pain came, he endured it.
Who knew how long passed before, at last, a thread of mental power that fused the heaviness of "mountains," the fierceness of "burning," and the sharp intent of "piercing" successfully completed an entire tempering cycle in the heart fire.
When that thread of mental