It didn't take long before the pill furnace began to shake violently, then released a massive amount of energy in an instant.
Lin Yifan knew that the spiritual energy within the spirit stones had been catalyzed; he hurriedly continued the refinement.
The nascent form of the Yuan Force Pill that had just formed in the furnace had the ability to absorb and condense energy, sucking back the released energy; therefore, all he needed to do was use his cultivation power to stabilize the furnace.
The energy inside the furnace surged wildly, Lin Yifan almost exhausted all his strength to stabilize it; however, even so, he was still unable to stop the tremors of the furnace; gradually, he felt an invisible force pressing on him, making him uncomfortable.
This was the result of opposing forces; if his power could not withstand the energy in the furnace, then he would be injured by a reactionary force.
