I'm Already an Invincible Great Emperor, Why Should I Shore Up My Weaknesses?

Li Xu attained enlightenment and became an emperor in the Desolate Realm, unrivaled beneath the heavens and mighty throughout the cosmos. He was powerful enough to deter even the forbidden beings of this world and the realms beyond from invading the mortal world. Yet this peerless powerhouse received a wondrous treasure that promised to shore up his shortcomings. 【Your lifespan is running short, and you are about to enter old age. I grant you one Immortal Elixir of Deathlessness, which can renew your lifespan and give you a new life.】 Li Xu was stunned. Then he refined the elixir and truly lived a second life. 【Your Heavenly Fire Dao is flawed. You may comprehend the Primordial Immortal Sun and perhaps transform your Dao.】 Li Xu then received a stone containing the Primordial Immortal Sun. From it, he sensed the ancient, primordial aura of the sun. After ten thousand years of study, he transformed his Heavenly Fire Dao into the True Immortal Sunfire Dao and successfully entered his third life. 【You have spent years fighting, and your imperial body is damaged. But your battle spirit remains strong. You may enter the River of Time and fight the emperors of every age to forge a divine battle body.】 As it turned out, Li Xu could enter the River of Time at will through the wondrous treasure, striking down emperors from the past, present, and future. After countless battles, he truly forged a divine battle body, broke through into his fourth life, and achieved combat power on the level of a Heavenly Emperor! Faced with Li Xu, who kept defying death and beginning new lives, the world was baffled. Forbidden beings of the mortal world: “What is with this guy? One life after another. Is he just refusing to die?” The realms beyond: “Is a Human Heavenly Emperor about to appear, one who can sweep through all the worlds?” Geniuses of the Desolate Realm: “The Great Emperor reigns in this age, suppressing the myriad Daos and cutting off our path to enlightenment…” And yet. After breaking into his fourth life, Li Xu used his Heavenly Emperor-level power to shatter the shackles imposed by the Desolate Realm’s supreme heavenly will, freeing the myriad Daos so that the realm could give birth to new emperors. But even the new emperors could only serve as foils to Li Xu. Li Xu continued to shore up his shortcomings until he became an immortal in the mortal world and was revered by all the realms. But then the Mythic Tribulation arrived, bringing him a new challenge…