Watching Six Luminaries Immortal depart, Chen Nianzhi wasted no time and immediately entered seclusion to refine and advance the Heavenly Separation Twin Swords.
To advance a natal immortal treasure to the superior grade, there were no more than three problems that needed resolving.
First, its master's cultivation had to reach the late stage of Immortal Ascension. Otherwise, insufficient cultivation would naturally make it impossible to nurture the immortal swords.
Second, one's formation mastery had to reach the superior immortal rank. Only a formation master of this level could transform laws into formation patterns and deduce the natal formation patterns of a superior-grade immortal treasure.
Third, an immense quantity of Five Elements essence was needed. Without enough Five Elements essence to nurture it, the immortal swords would likewise be unable to complete their final transformation.
Of these three conditions, Chen Nianzhi had already met the first.
Although his cultivation was insufficient, he had long ago used Primordial Violet Qi to unlock the shackles of the Heavenly Separation Twin Swords, so he could naturally cross this threshold.
The second condition was actually quite difficult. Superior immortal formation masters were exceedingly rare. Without extraordinary talent in the Dao of formations, an ordinary immortal might study for hundreds of thousands of years without necessarily reaching such a level.
Chen Nianzhi possessed exceptionally high comprehension, and he also had Earth Immortal Xuanxin's notes to draw upon. He had already crossed this threshold as well, successfully deducing the method for advancing the Heavenly Separation Twin Swords.
What remained now was simply to continually nurture and refine them, integrating the Five Elements essence.
Now that he had gathered all the Five Elements essence, the rest was merely a matter of steady grinding and the expenditure of time.
Chen Nianzhi settled his mind and began refining his natal