Heavenly Core Refinement was more tedious and time-consuming than he thought. It was even more tedious than opening his meridian. The process was filling his dantian to the brim, until his dantian cracked, a subtle crack. Then he would use his Heavenly Energy to nurse his Dantian, which required meticulous attention as he needed to make sure the crack was mended before filling his Dantian again.
He repeated the process again and again, which was why it was boring even compared to the Meridian Opening Art. It required patience, or else he might damage his dantian. As long as he was being careful, everything should be safe. He just needed to do a triple check to ensure the crack was mended before continuing.
