The old man, in his youth, had once fought with someone and was invaded by their sinister energy, suffering severe injuries.

He sought treatment from a physician at the time and was cured, but it turned out the physician was incompetent. The sinister energy wasn't completely expelled and instead settled deep within his meridians, leaving a hidden ailment.

This ailment wasn't much of a problem in the past. However, after fermenting for so many years, and having cultivated from the Innate Realm to the Divine Sea Realm, this hidden ailment became as stubborn as a bone-deep parasite, extremely difficult to remove.

He had consulted many physicians, including renowned ones, and even sought help from great cultivators at Jixia Academy.