The two hid their bodies and swaggered into starshine fake eye Gu's range, and they indeed did not attract any Gu Immortal's attention.
Along the way, the two found similar types of investigative Gu like starshine fake eye Gu.
Some of these Gu worms were buried in the ground, some were disguised as tree leaves, and some were hidden in brooks, drifting with the water.
Fang Yuan used his methods one by one, sometimes invisibility, sometimes Gu worms directed at countering them, or tunneling under the ground or swimming through water, all kinds of methods to slip past these investigative Gu worms.
The two had wanted to move until they were below the eighth star hall, and the shortest way would be a straight line to the eighth star hall. If they got a chance, they could also quickly react and use the shortest amount of time to charge to the eighth star hall, and fish benefits from the messy situation.
However, as they walked through this straight line, a bloody odor assailed their noses from ahead.
Fang Yuan and Hei Lou Lan glanced at each other, the latter revealed a doubtful look as she used her divine sense to transmit: "Strange, both the amount of investigative Gu in this path and their types are increasing more and more."
"Let's take a look." Fang Yuan replied.
The two cautiously evaded or deceived the investigative Gu worms, and discovered further traces of battle.
After a while, they finally reached the area where there was the most intense odor of blood.
They saw a black leopard's corpse lying on the shattered and disordered pile of rocks.
The black leopard was as large as an elephant. Its fur was glossy and shiny, full of wild charm. The remaining aura showed the black leopard's identity, a genuine desolate beast.
"This desolate beast is a vanishing shadow leopard." Fang Yuan said in a low voice.
"It is that someone killed this vanishing shadow leopard and yet left behind its corpse here?" Hei Lou Lan revealed a trace of doubt.
Fang Yuan squatted down near the ground, and used his hand to feel the gully beside his legs.
He then took out a time path Gu worm and carefully activated it.
This Gu worm had the appearance of a crystal sphere, and was an extremely rare rank five Gu. Its name was backtrack Gu, an investigative Gu under time path, which could backtrack to the past events within a specific range.
Backtrack Gu was activated; it displayed a blurry and mute battle scene.
In the scene, two giant figures were in an intense battle while a small figure was standing far away to the side.
Backtrack Gu was only a rank five mortal Gu, and whether it was Shi Lei, the vanishing shadow leopard or Star Lord Wan Xiang, they were all rank six or above, immortal bodies and desolate beast bodies had dao marks, thus backtrack Gu's investigative ability was restrained greatly.
Hei Lou Lan came closer and watched the battle.
The mute battle scene was extremely blurry. But they could roughly guess that one of them was the vanishing shadow leopard from the approximate build.
And the one battling with the vanishing shadow leopard did not seem to be a human but a tiger desolate beast.
The one standing far away had a human shape and could be a Gu Immortal. But their appearance was blurry and they could not be sure.
Not only this, the battle scene broken off intermittently and was not coherent.
Fang Yuan and Hei Lou Lan observed the battle with all their attention, for a moment, other than the slight breeze in the mountains, there was no other sound.
After a dozen breaths of time, scorching smoke started to curl up from the backtrack Gu and the battle scene suddenly disappeared.
The backtrack Gu had died as a result of forcibly recreating the image of the Gu Immortal level battle.
Fang Yuan felt slight heartache, and put the scorched corpse of backtrack Gu back inside his immortal aperture to get rid of any traces.
He had been gathering this backtrack Gu from treasure yellow heaven recently but even then, he only had a total of fifty to sixty. This was still the case when the five regions were in peaceful times, during the chaotic war of the regions, backtrack Gu would be widely used and very hard to get, it would be a case where one would have to produce them for their own use, treasure yellow heaven would simply have none for sale.
Hei Lou Lan was very interested: "This Gu worm is quite ingenious, what is its name, did you buy it in treasure yellow heaven?"
The varieties of Gu worms in existence were as vast as the ocean. Moreover, Hei Lou Lan cultivated strength path, not time path, and her understanding of other paths was only at the basics, limited to the typically used Gu worms.
Gu worms like backtrack Gu were classified as rare Gu of another path, it was normal for her to not know of it.
Fang Yuan did not reply, instead he took out another Gu.
He had refined this Gu himself based to his memories. According to the course of history, this Gu should have only appeared three hundred years later, its name was thread trace Gu.
Its appearance was quite special, resembling a small horsewhip which children from Northern Plains played with as toys. Fang Yuan used his enormous, monstrous zombie claws to grab it, making its small size even more apparent.
Fang Yuan grabbed the handle of the horsewhip and softly whipped at the air in front of him.
Crack. The empty air suddenly showed traces of marks.
"What is this?" Hei Lou Lan gazed at the marks without blinking.
Crack crack crack.
Fang Yuan whipped the horsewhip like thread trace Gu repeatedly, the marks in the air continued to increase.
Hei Lou Lan watched the whole process and soon was able to sense that the space Fang Yuan was whipping at was the area where the fight in the battle scene had occurred, and also the area where that blurry Gu Immortal had been standing.
As various thoughts flashed past, Hei Lou Lan's pupils slightly enlarged, blurting: "Could these marks be dao marks?"
Fang Yuan gave a contented smile at this moment: "Right, they are dao marks. Whether it be Gu Immortals or desolate beasts, they are filled with dao marks, and any area they stop at will leave behind dao marks for a short period of time. It is just that these dao marks are extremely weak, that even Gu Immortals paying close attention won't be able to sense them, that is, unless they use this thread trace Gu that I researched. From observing these dao marks, I can infer some information on them."
Fang Yuan once again brazenly took on someone else's creation from his previous life as his own.
"Thread trace Gu...." Hei Lou Lan mumbled, her gaze towards Fang Yuan had changed a little.
Fang Yuan pointed towards the area where Star Lord Wan Xiang had stood previously: "Look, the dao marks have manifested and formed a human shape. The color is azure blue which means a star path Gu Immortal had been observing the battle. The greater portion of the dao marks had stayed there and although there are some dao marks in the surroundings, they are mostly tightly enclosed around the greater portion, this means that star path Gu Immortal had only been observing from the side during the whole battle. And looking at the concentration of the dao marks, it seems to be a rank six Gu Immortal."
Hei Lou Lan looked at the direction Fang Yuan pointed towards and listened to him, paying full attention.
Fang Yuan then pointed at the area where the vanishing shadow leopard died, there were remaining dao marks of black color for dark path and red color for fire path.
He continued: "The dark path dao marks clearly belong to the vanishing shadow leopard while the red colored dao marks belong to the existence that killed the vanishing shadow leopard. As for their identity, whether they are man or beast, that is still not certain. Look at how concentrated these dao marks are and how they are intertwined with each other, this shows that the battle was very intense. The dark path dao marks are sparse while the red colored dao marks are rather dense, we can deduce that the existence that killed the vanishing shadow leopard is also at least of rank six realm."
Hei Lou Lan's mouth widened slightly as she listened to Fang Yuan.
Her gaze towards the thread trace Gu in Fang Yuan's hand became slightly burning.
This thread trace Gu was only a rank five mortal Gu, but it was very useful. With just this Gu, one could infer so much useful information.
The key thing was the thoughts involved in refining it were very special, and it could even be said to have blazed an unexpected new trail that bypasses common logic.
Hei Lou Lan might have just recently advanced into a Gu Immortal, but she understood the importance of information and started to give more significance to Fang Yuan 'invention', thread trace Gu.
Had Shi Lei and Star Lord Wan Xiang been here, they would probably be soaked in cold sweat.
They had used mainstream investigative methods and counter-investigative methods, but thread trace Gu just happened to pierce through the gap in them. Fang Yuan's methods were from the time of the chaotic war of the five regions after all, the materialization of the intelligence of the whole five regions, it was like they were over half an era ahead of current Gu Immortals, naturally they had huge superiority!
Crack crack crack.
Fang Yuan lashed the horsewhip several times, many more dao marks appeared but also many more disappeared.
These dao marks were very weak and were gathered together by thread trace Gu, thus greatly shortening their already limited lifespan.
Dao marks entangled mutually, getting more disorderly. Fang Yuan finally stopped lashing the horsewhip and sighed: "This is more or less the ability of this thread trace Gu, the manifestation of dao marks lasts only for a period of time and requires the observer to have plenty of experience. Moreover, activating Immortal Gu also leaves behind responding dao marks. In an intense battle, many abilities and methods are used, causing the dao marks to entangle and become extremely chaotic with no way to infer anything. However, fortunately, few methods were used in this battle, so we are able to roughly understand the situation."
Hei Lou Lan's eyelids twitched.
Inferring so much useful information with a mere rank five mortal Gu and still not satisfied?
Her gaze firmly locked upon the thread trace Gu until Fang Yuan stored it back in his immortal aperture. She keenly discovered that the formerly intact thread trace Gu's whip-like body was full of cracks now. Clearly, there was a price to pay for manifesting the dao marks.
Hei Lou Lan inwardly estimated, this thread trace Gu could be used for two more times at the minimum. Immediately, her evaluation of thread trace Gu increased by another level.
It could be used for a total of three times!
A mere rank five Gu worm could be used three times to investigate into existences of rank six level and obtain so much information.
Just as Hei Lou Lan was unable to endure and was about to ask if Fang Yuan was selling thread trace Gu, Fang Yuan took out another investigative Gu worm.
This was only a qi path Gu worm which Fang Yuan used to draw in the surrounding scents.
Next, Fang Yuan stored this qi path Gu worm and took out another Gu worm.
He moved everywhere around the battlefield and activated Gu worms from time to time. Hei Lou Lan was only able to recognize a small portion of these Gu worms, but it was also not to the extent where she was certain. The remaining greater portion, Hei Lou Lan simply had no idea, unable to recognize any of them.
She subconsciously pursed her lips, as she for the first time felt that Fang Yuan had unfathomable depths.
During the journey in Northern Plains, she only felt that Fang Yuan was experienced and astute, and a major enemy. When cooperating with Fang Yuan, she had no choice but to do so, and was very aware that it was asking for favors from a tiger.
She got Fang Yuan's help to pass through her tribulation and become a Gu Immortal, she had thought she could suppress Fang Yuan a notch. But soon, Fang Yuan used her and Fairy Li Shan to scare even Immortal Crane Sect's Gu Immortals away. The whole thing was won before engaging in battle, which gave no chance for Hei Lou Lan to make a move. Since there was no loss in battle, Fang Yuan did not have to pay twice the compensation, it was akin to him obtaining his objective without losing anything.
In contrast, to coax Fang Yuan to make an effort, Hei Lou Lan had to give the precious true meaning infusion of Reckless Savage Demon Venerable to him. Fang Yuan was also truly ruthless, he swallowed it whole without leaving behind anything to Hei Lou Lan.
Later, Fang Yuan started the guts Gu business and took the initiative to share profits with Hei Lou Lan and Fairy Li Shan. Although he needed Hei Lou Lan's strength qi Immortal Gu in the process, Hei Lou Lan did not feel comfortable the whole time, it seemed as if she was being controlled.
Now, Hei Lou Lan felt a shiver in her heart as she looked at Fang Yuan using these methods.
These small methods all used mortal Gu and were seemingly unremarkable, but Hei Lou Lan was a discerning person, how could she not understand the profound significance represented by these small methods!