Having made his decision, Han Li naturally no longer hesitated. He flipped a palm over, and the jade slip that the elderly man had given him appeared in his hand.

On this occasion, he was going to study the refinement method for the flying swords before he worked on the sword art.

He had already briefly read through the refinement method last time, but this was an important matter, so Han Li naturally had to read it again in detail.

A short while later, Han Li withdrew his spiritual sense from the jade slip and narrowed his eyes slightly in contemplation.

According to the jade slip, if he wanted to rid his flying swords of impurities, there were three methods he could employ.

The simplest of those methods required no extra materials; he simply had to use his Nascent Soul flames to slowly refine all of the non-wood-attribute materials in the flying swords.

That was the simplest method and also one that incurred the least amount of risk.

However, all of the materials in his flying swords had already fused as one, and it would take an extremely long time to refine them in such a way. In fact, even three or four centuries may not be enough. During this process, he'd have to constantly be using his Nascent Soul flames, so he'd be significantly hampering his own cultivation.

As such, Han Li decided against this method almost immediately.

The second method was to use a cultivation art known as the Nineflame Metal Melting Art. If he could collect several types of special fire-attribute pills, then go into seclusion for around 70 to 80 years, he'd be able to use this cultivation art along with the power within those pills to forcibly rid the Azure Bamboo Cloudswarm Swords of their impurities.

However, this was an extremely risky method, and it would also harm some of the wood-attribute materials in the flying swords. Furthermore, the fire-attribute pills required were quite rare and not that easy to collect.

At the time, the elderly man was preparing to use this method to refine Han Li's flying swords for him in exchange for Golden Lightning Bamboo, but Han Li had not been a fan of this essentially self-mutilating method.

As such, there was only one final method left, and it was also seemingly the most implausible and time-consuming one.

The elderly man had enclosed a message stating that this method was only something that he theorized would work, but had never actually tried it himself. However, if one were to follow the instructions closely, they should have a good chance of success. Furthermore, if success were to be achieved, the rewards reaped would also be quite staggering.

This method involved a process that was known as "planting swords".

The process consisted of finding some spirit seedlings, then planting them in a place with abundant spiritual Qi. After that, the flying swords had to be sealed within these seedlings, and as the seedlings grew, all of the materials in the sword would gradually be converted into wood-attribute materials due to the wood-attribute spiritual Qi of the spirit trees themselves. As such, there'd be no need to rid the flying swords of anything.

Once the spirit trees reached full maturity, the flying swords would've been nurtured by wood-attribute spiritual Qi for a long time. As a result, not only would this process not harm the swords, it would make them pure to an incredible degree.

Even though that wouldn't significantly enhance the power of the swords, it would make it a lot easier for Han Li to attain oneness with his swords.

Of course, the elderly man didn't employ such a brilliant method due to a fatal flaw; it simply took too long!

It would take a far longer time than the previous two methods to achieve this method as spirit trees had to grow bit by bit. Even the most ordinary of spirit trees required at least 1,000 years of nurturing care to reach full maturity.

During this time, not only could these flying swords not be used at all, it also had to be ensured that none of the spirit trees died. Otherwise, all of the prior efforts would go to waste. Even if one were to replant the flying sword into another spirit tree, the damage would already be irreversible.

As for how long was required for this process, there were no specific guidelines. However, one thing was for certain; the longer a sword was planted and the more precious the spirit tree was, the greater the degree of purity of the flying sword following the procedure.

Han Li was ecstatic to see this method, and he immediately decided to use it.

This method would perhaps be next to impossible for other people, but it was perfect for him, seeing as he could accelerate the growth of plants.

With his small vial to assist him, Myriad Year Spirit Trees could be nurtured with no issues at all.

However, he was rather skeptical about whether this method was actually feasible.

However, he didn't have to expend a lot of time to complete the process, so he decided to give it a try first.

If it didn't work, then he could switch to one of the other two methods.

Having made his decision, Han Li rustled a sleeve, and a green jade box appeared.

The lid of the box flew off to reveal a seemingly ordinary section of bamboo that had a few roots hanging off one end.

This was none other than the small section of Golden Lightning Bamboo that Han Li had intentionally kept after refining his flying swords.

Even though this wasn't explicitly stated in instructions within the jade slip, it could only be better to plant the swords into a spirit tree that was the same as their main constituent material. Furthermore, he had learned from the elderly man that the leaves of the Golden Lightning Bamboo could be used to refine the Golden Devil Vanquishing Lightning, so it certainly couldn't hurt to harvest some of those leaves as well.

Thus, Han Li summoned his second Nascent Soul again before handing the wooden box and a flying sword over to it.

He was going to experiment with just a single sword first. If the process did indeed prove to be viable, he'd then mass produce Golden Lightning Bamboo and plant the rest of his swords into them.

After the second Nascent Soul departed, Han Li closed his eyes to meditate for a while before opening his eyes again and producing a small white vial.

He raised his neck and dripped a drop of True Toad Liquid into his mouth to finally begin his true cultivation.

Treasures and cultivation arts were certainly fantastic, but without sufficient magic power to support them, they would hardly be very useful.

Han Li had been well aware of this all along.

He made a hand seal, and golden light shimmered all over his body as the true devil projection appeared again.

Each of its six golden arms made a profound hand seal, and the projection also sat down in a cross-legged manner as if it were also going to cultivate.

At the same time that golden light flashed from Han Li's body, a halo of golden light also appeared around the projection.

This massive halo of light enshrouded the entire projection, and countless golden runes were surging forth relentlessly from the projection's hands, then disappearing into its body.

Meanwhile, Han Li sat expressionlessly with a layer of golden scales over his body, and spiritual light swirling over the surface of his skin, giving off quite a mysterious image...

Days turned into months, and months turned into years, but the doors of the secret chamber remained firmly shut throughout this entire time.

During this period, the second Nascent Soul would control a giant ape puppet's body to occasionally appear in the medicine garden before quickly disappearing.

The mid-grade demon beasts of the Hidden Black Mountains also visited on several occasions, bringing with them large amounts of precious materials exchange for Woodbud Flowers.

All of them wore grim expressions each time, thinking that the supply of Woodbud Flowers surely had to be rapidly depleting, but the second Nascent Soul only had to nurture some Woodbud Flowers from time to time in order to continue facilitating these exchanges. In the process, the Weeping Soul Beast transformed into Han Li's appearance to placate these demon beasts, thereby managing to convince them that Han Li was seeing them in person.

The demon beasts were naturally quite relieved that "Han Li" was able to continue supplying Woodbud Flowers.

Time passed by in a flash, and over 100 years flew by in the blink of an eye.

No major events took place on the island during this time, and it seemed that this period of peace would continue for the foreseeable future.

However, one day, an extremely astonishing phenomenon suddenly appeared in the air above Han Li's cave abode.

Loud thunderclaps erupted overhead, following which white spiritual clouds appeared out of thin air, then converged toward the summit of the mountain.

Countless specks of light of different colors also began to rise into the air from all of the mountains within a radius of thousands of kilometers. After rising to a certain altitude, these specks of light swelled before bursting like bubbles, creating swaths of five-colored light that then surged toward Han Li's cave abode.

Within 10 minutes, layer upon layer of dense five-colored light had enshrouded the entire mountain that Han Li was situated in, yet another phenomenon appeared in the air above.

The white spiritual clouds up above converged to form a massive cloud ring, at the center of which gusts of fierce azure winds were taking shape. The five-colored light down below was swept up into the cloud ring, then torn apart before fusing together again.

As the winds grew fiercer, the more and more five-colored spiritual light was swept up into the sky, and in the even the azure winds were converted into all types of different colors. However, the five-colored light surging from all directions didn't cease in the slightest, and the films of light around the giant mountain down below became even denser than before.

Such astonishing scenes naturally attracted all of the attention of the beasts and demon beasts within the Hidden Black Mountain Ranges.

The immense spiritual pressure from the phenomena alone was enough to force normal beasts to the ground as they trembled uncontrollably with fear, and even the normally ferocious beasts were completely petrified and powerless.

Some low-grade and mid-grade demon beasts that had attained intelligence hurriedly flew toward Han Li's cave abode, yet all of them seemed to have encountered an invisible barrier thousands of kilometers away from the phenomena, thereby preventing them from advancing any further.

All of them were forced to look on at the gargantuan cloud ring and five-colored mountain from afar with panic in their eyes.

The cow-headed beast, the three-headed giant python, and all of the other demon beasts that had made deals with Han Li also appeared in the nearby area.

All of them immediately identified where the phenomena were taking place, and all of them glanced at one another with astonishment in their eyes.

"Is that man making a breakthrough? Could it be that he's becoming a Great Spirit General?" the three-headed giant python exclaimed.

"That's most likely the case. A less significant breakthrough wouldn't conjure up such an astonishing set of phenomena," the cow-headed beast replied in a slow voice.