The door to the pill-refining chamber remained shut for a full three years.
When Han Li finally emerged one day, calm and unhurried, every last demon core had been transformed into various rare and precious pills.
During the first two years, Han Li had naturally devoted all his time to refining pills whose primary ingredients were fifth-grade demon cores.
Although these pills no longer held any notable benefit for someone at his current level, any single one of them, if it fell into the hands of a Foundation Establishment cultivator, would be an object of wild joy — something they had dreamed of possessing.
Through this extensive pill-refining practice, Han Li's mastery of alchemy had climbed yet another level.
After all, even a genuine pill-refining grandmaster would never have the opportunity to squander such a vast quantity of demon cores on unrestricted practice.
An ordinary alchemist would consider it extraordinary if he could use thirty or forty demon cores over the course of his entire life.
Although each type of pill had its own significantly different refining method, there were always certain commonalities that Han Li could draw upon.
As a result, after all this repeated refinement of rare pills, his alchemical skill had been pushed forcibly to a level slightly above that of the rumored pill-refining grandmasters.
This, in turn, meant that when Han Li later used sixth- and seventh-grade demon cores, his success rate improved considerably.
It was a source of immense satisfaction!
Otherwise, given the rarity of sixth- and seventh-grade demon cores, even Han Li would have been reluctant to waste them lightly.
Once the pill-refining was complete, Han Li rested for a month.
During this period, he visited the insect chambers several times to check on the three-colored Gold Devouring Beetles and the unevolved Gold Devouring Beetles in their respective rooms.
While he had been in the pill-refining chamber, he had instructed his puppets to take turns feeding both groups of beetles the Bloomleaf Rainbow Robe Grass.
The result was a piece of news that was terribly disappointing to Han Li.
Although the three-colored Gold Devouring Beetles continued to eat the Rainbow Robe Grass without issue, the grass seemed to have lost the special property that once drove the beetles into a frenzy of excitement. After consuming it, they showed absolutely no unusual changes.
At first, Han Li assumed the time had been too short and the number of beetles too large, which was why the grass's effects seemed so negligible.
So, out of suspicion, he had several hundred three-colored Gold Devouring Beetles specially isolated and fed nothing but this grass, to observe any changes in their behavior.
But after several feedings, these beetles remained exactly as before, with no abnormal reactions whatsoever.
This left Han Li feeling thoroughly vexed.
He could now conclude with certainty that the Rainbow Robe Grass had truly lost its miraculous ability to stimulate reproduction in the evolved Gold Devouring Beetles.
He did not know what hidden mechanism lay behind this, but without question, he had lost his method for rapidly breeding and advancing the three-colored Gold Devouring Beetles.
These beetles were now a dwindling resource — one fewer each time one died!
All he could do now was return to the old method and have the puppets concentrate feeding the Rainbow Robe Grass on the gold-and-silver-colored, unevolved Gold Devouring Beetles.
These beetles were growing increasingly irritable with each passing day, suggesting that their next cycle of reproduction was not far off.
Only after dealing with all of this did Han Li collect his thoughts and enter the sealed cultivation chamber.
He planned to use various pills to assist him in first mastering the eighth layer of the Green Elemental Sword Technique, so as to break through to the mid-stage of Core Formation.
Seated cross-legged on a meditation cushion in the chamber, Han Li pulled a pre-prepared medicine bottle from his storage pouch.
He tipped out a pill that glowed with a faint red light, looking much like a longan fruit, placed it into his mouth with one hand, tilted his head back, and swallowed it.
Feeling the medicinal warmth begin to spread through his abdomen, Han Li silently recited the incantation for the eighth layer of the sword technique and slowly closed his eyes.
...
Time flew like a shuttle; the years passed without mercy.
While Han Li devoted himself wholeheartedly to cultivating the sword technique and refining his magical power within his cave dwelling, the months and years slipped by unnoticed.
The process of constantly consuming pills and then converting the medicinal power into spiritual energy was mind-numbingly tedious.
Fortunately, Han Li was single-mindedly focused on perfecting the technique so that he would possess the strength to protect himself. With that thought driving him, he did not find the hardship too oppressive.
Fifteen or sixteen years passed in the blink of an eye.
At last, Han Li broke through the bottleneck of mid-stage Core Formation and completed the eighth layer of the Green Elemental Sword Technique.