The Planar Pearl is something from ancient times, filled with the will of many Great Sages and even one Demi-Immortal. The Pearl is what keeps the hordes of fiend-devils in the void from being able to enter the Rich-Lush Continent and invade. Over the years, the Pearl has been battered by horde after horde of fiend-devils, slowly wearing the will of those ancient experts down until they were in the grip of despair. Eventually, those fiend-devils would have been able to completely corrupt the Planar Pearl and then enter the Continent.
Yang Qi was given what would have been a suicide mission for anyone else by the Chancellor of the Demi-Immortal Institute to repair the damage to the Pearl; Mission: Mend Heaven.This mission was meant to be a test by the Chancellor of Yang Qi's mysterious backer, hoping to have the backer come out in person. Thankfully, under the watchful of eyes of both the Chancellor and his daughter, "Young Lady", Yang Qi was able to repair the Planar Pearl 100% and even wake up the wills of the ancient experts within, leading to them blessing Yang Qi as a representative of the Legion of Gods, further increasing his cultivation.
Healing the Planar Pearl not only keeps the hordes at bay, it also reestablishes the many space-time wormholes that connect to the Rich-Lush Continent from many other planes of existence, such as the Quake-Dawn Continent. It also heals the Continent in general and improves things like the Minorcosm World within the Demi-Immortal Institute to be as large as it was in the past.