Of course, in reality, even if the Gathering Spirit Jade still works, it wouldn't be of much use to Zhang Yanhang, because the Gathering Spirit Jade relies on increasing the density of spiritual energy around him to enhance his own energy value recovery speed.

But now he no longer needs to recover his energy value by operating the Limitless Universe Skill like before; instead, he can just let the Heaven and Earth Devourer operate automatically to continuously recover energy value. And such things that only serve to increase the spiritual energy density naturally can't provide a bonus to the Heaven and Earth Devourer.

After deploying the Alchemy Array on the mountaintop, Zhang Yanhang successfully extracted the Nine Yang Heavenly Heart Grass originally located in the mountain belly within just a few seconds.

This Nine Yang Heavenly Heart Grass is surrounded by a circle of round leaves on the outside, totaling nine, and in the center grows a fiery red stamen. Don't ask him why a piece of grass would grow a stamen; Zhang Yanhang doesn't know either. All he can say is that Heavenly Materials and Earthly Treasures might just be this willful and beyond common sense.

But Zhang Yanhang clearly doesn't care much about appearances; he is only interested in the specific effects, so he immediately swallowed the Nine Yang Heavenly Heart Grass into his Stomach Space.

After feeling that familiar warm current surge within his body, Zhang Yanhang's evaluation is 'very fresh, very delicious.' Based on his years of consuming physical-type Heavenly Materials and Earthly Treasures, the Nine Yang Heavenly Heart Grass just now probably helped him increase his stamina limit by about thirty percent.

"Fifth-tier Heavenly Materials and Earthly Treasures are indeed extraordinary. Just casually eating one Nine Yang Heavenly Heart Grass directly helped me increase my stamina limit by thirty percent. If converted into constitution attribute, it would take at least several points to achieve that level of increase."

Of course, besides the effect of the Nine Yang Heavenly Heart Grass itself, Zhang Yanhang feels that the Swallowing Heaven and Earth Skill must have played a role in providing a bonus. So, he thinks the original Nine Yang Heavenly Heart Grass could at most provide about a twenty percent increase in the stamina limit, and the additional increase obviously comes from the bonus of the Swallowing Heaven and Earth Skill.

After eating the Nine Yang Heavenly Heart Grass, Zhang Yanhang casually performed a Seeking Fortune and Avoiding Evil test, and the result actually suggested that his increase in stamina limit might be slightly more than thirty percent.

Therefore, speaking purely from the number of times he can release Death Waves, his Death Wave release count has now increased from the original 118,400 times to 156,300 times, which is an increase of approximately 37,900 more Death Wave releases.

"Indeed, other than advancing in rank, the best way to increase stamina is always through Heavenly Materials and Earthly Treasures."

Zhang Yanhang even feels that an XXX-level Talent Immortal Life in terms of stamina limit doesn't offer as much growth as Heavenly Materials and Earthly Treasures do, after all, Heavenly Materials and Earthly Treasures can be obtained for free, and one can even get them for free multiple times a day.

Of course, Zhang Yanhang also believes this viewpoint applies to defensive-type Heavenly Materials and Earthly Treasures as well, except that after advancing to the fifth tier this time, he hasn't had the chance to acquire any Heavenly Materials and Earthly Treasures yet, so he doesn't know what the situation is with defensive-type Heavenly Materials and Earthly Treasures at the fifth tier.

"According to the calculation of covering 10.5 square kilometers with each Death Wave, my current 156,300 Death Waves should now be able to cover a total area of 1,641,140 square kilometers.

Moreover, this calculation does not include Life Drain. If Life Drain is included, it increases by another thirty percent, becoming a total of 2,133,495 square kilometers in coverage area. When the base increase becomes higher, any small enhancement can turn into a very exaggerated number."

Zhang Yanhang remembers that not long ago his total coverage area was only about 1,510,000 square kilometers, and now just by casually consuming a piece of Heavenly Material and Earthly Treasure, the total coverage area has increased by 620,000 square kilometers.

"In terms of the multiplication of stamina limit, my original stamina limit was roughly sixteen times that of a peak fourth-tier, and now it has directly increased to twenty-one times that of a peak fourth-tier, which equates to roughly a fivefold increase in stamina limit.

It would be great if my strength could increase as quickly just by consuming Heavenly Materials and Earthly Treasures..."

Unfortunately, Zhang Yanhang has not encountered any Heavenly Materials and Earthly Treasures that could enhance strength or movement speed, perhaps because such Heavenly Materials and Earthly Treasures are indeed relatively rare.

"Speaking of which, this time the excess bonus doesn't seem to have taken effect... Could it be that it doesn't work on Heavenly Materials and Earthly Treasures? That is also quite possible."

As a newly acquired ability, Zhang Yanhang, although he has inquired about it through Multiple Choice, still doesn't understand the operational principle of excess bonus. Hence, he feels it's normal if the excess bonus doesn't apply to Heavenly Materials and Earthly Treasures.

"The largest province in the Empire is only 1,660,000 square kilometers, so my current total coverage area has surely surpassed the provincial level and is beginning to approach a national level.

Zhang Yanhang's previous total coverage area could only cover the total of those ranked below the top sixteen provinces, and now it has once again merged with the sixteenth-ranked Guizhou, fifteenth-ranked Guangdong, and fourteenth-ranked Hubei, totaling 2,055,000 square kilometers for these twenty-one provinces combined.

The next target Zhang Yanhang needs to merge with is the thirteenth-ranked Jilin, which has 187,400 square kilometers.

Considering the rapid growth trend he is experiencing in terms of Heavenly Materials and Earthly Treasures, Zhang Yanhang believes this small target can be easily achieved.

Meanwhile, Zhang Yanhang, who could originally only cover four Japans at a time, can now cover five and a half.

"From the perspective of country size, my coverage was just enough to surpass the seventeenth-ranked Iran with 1,650,000 square kilometers, but now I have successively surpassed Libya's 1,760,000 square kilometers, Sudan's 1,880,000 square kilometers, and Indonesia's 1,910,000 square kilometers."

In fact, Zhang Yanhang has even surpassed the thirteenth-ranked Mexico with 1,960,000 square kilometers.

And Zhang Yanhang's next small target is the 2,250,000 square kilometers of Saudi. To be honest, Zhang Yanhang never knew that Saudi is actually larger than Mexico, always having the subjective impression that Saudi was a small regional country with an area much smaller than Egypt.

After dealing with the Nine Yang Heavenly Heart Grass, Zhang Yanhang didn't rush to leave but decided to deal with a small matter before going. As for what this small matter is, it's naturally a few low-level ghosts he detected when scanning across Juyang County, so he plans to deal with them on the way.

But when Zhang Yanhang instinctively flew directly to the female ghost near a tomb in the suburbs, he suddenly realized he didn't have a good method to capture the female ghost.

Or maybe, there's another way to put it: getting rid of these female ghosts is extremely simple for Zhang Yanhang. He can handle it however he wants, but capturing them? He's never tried that before. After all, not only does he have to consider how to catch them, but also where to put them after he's done.

"Can they exist directly in the Stomach Space? But won't the Stomach Space directly absorb this female ghost?"

Zhang Yanhang remembers that his Stomach Space seems to only adjust the absorption efficiency of matter and energy. Seems there was no mention if souls can be adjusted, or perhaps souls are categorized as a type of energy?

Looking at the female ghost in front of him, whose chest is as flat as a board that looks like her back, Zhang Yanhang couldn't help but think of one thing... Oh, wait, that is the back! This female ghost's head is turned backward.

"Forget it, let's just swallow her directly. We'll find out naturally if there is any use to it."

Zhang Yanhang immediately opened his mouth and swallowed the female ghost who had been hovering around him, trying to tie him up with her hair.

But just as soon as he swallowed her, Zhang Yanhang noticed something was off. The Stomach Space seemed to automatically determine the female ghost as an enemy. Before he could react, he heard the female ghost suddenly let out a tragic scream and then exploded like a balloon being popped, her soul scattered on the spot.

Of course, in the Stomach Space, whether you're scattered or not, you definitely can't escape. The Stomach Space prioritizes absorbing broken souls, and sure enough, it does so without wasting a single bit, ensuring every piece of soul residue is absorbed properly.

"Speaking of which, when I swallowed small fish and shrimp, including tangentially swallowing sharks and whales, they also seemed to be prioritized for absorption. Does the Stomach Space not support life forms?"

Zhang Yanhang thought carefully, realizing the Stomach Space must have some combat capability. Not supporting life forms and absorbing them forcefully may be normal, considering he has no control over the Stomach Space. After swallowing them, letting life forms wander inside would be silly.

"Since it doesn't support containing life forms and ghosts, I guess I really shouldn't allow the Stomach Space to directly devour ghosts. Otherwise, the souls would be absorbed by the Stomach Space before I have the chance to refine them into the Wise Man's Stone."

Zhang Yanhang thought he should come up with other methods to store ghosts.

"Can the Waist Bag store ghosts? No, the Waist Bag definitely can't store ghosts..."

After contemplating for a long time, Zhang Yanhang suddenly recalled he once picked up something called a Demon Refining Pot, which was seemingly used specifically for storing demons and ghosts.

"Since that's the case, looks like I'll have to use this ancestral Demon Refining Pot."

Zhang Yanhang rummaged through the Waist Bag for a while before finally finding the Demon Refining Pot, nestled inside a large package along with various Spiritual Artifacts he had obtained previously, like the Copper coin sword and Spiritual Jade Crown, totaling about a few dozen Spiritual Artifacts.

All he could say is that these were accumulated little by little over time. However, they could only be used in the Main World where he had little need for them, which is why they stayed in the Waist Bag untouched.

But Zhang Yanhang couldn't bear to simply discard them, as they were not easy to collect, so he just kept them piled up without bothering.

"Luckily, I didn't discard these Spiritual Artifacts before. Looking at it now, they can still serve some purpose."

Zhang Yanhang released Spiritual Energy from within to activate the Demon Refining Pot. To his surprise, its rank wasn't low, around Fourth Tier, should be sufficient for his use. He estimated there shouldn't be Fifth Tier ghosts in the Main World now.

And even if there are Fifth Tier ghosts, it's fine — at worst, he'd use Alchemy to forcibly convert them into Wise Man's Stone right on the spot. If they are Fifth Tier, they indeed warrant a separate refining.

As for other low-level ghosts, it's clear they wouldn't enjoy this treatment. He plans to accumulate more before refining them into Wise Man's Stone together, mainly because it's more convenient, as refining each time a ghost is caught would be too troublesome.

After finding a suitable container for ghosts, Zhang Yanhang promptly flew to the next location where ghosts hid, situated in a deserted kindergarten building in Juyang County.

Let's just say that with the declining birth rate, aging population, and negative population growth, private kindergartens are indeed far less popular than before. Many closed due to insufficient enrollment just a few years after being established, while public kindergartens barely survive.

In the office on the top floor of this abandoned kindergarten building, Zhang Yanhang found a hanging ghost. Looking at this middle-aged man in a suit with glasses, Zhang Yanhang believes he was probably the principal of the kindergarten, perhaps killed himself due to bankruptcy and debt repayment pressure.

For a middle-aged male ghost who was clearly modern but still opted for hanging as a suicide method, Zhang Yanhang was somewhat puzzled. After all, wouldn't jumping off a roof be more straightforward? You might even crush someone as a parting gift.

As for this middle-aged male ghost, who opted for ancient-style hanging suicide, Zhang Yanhang could only assume he might be nostalgic, or perhaps the kindergarten's height wasn't enough. Observing that this kindergarten only has three floors, around eight meters tall, you might indeed survive a fall.

This middle-aged male ghost, burdened with immense pressure in life, for some reason remains hanging from the rope. Perhaps he indeed prefers the rope.

But for that reason, hanging on the rope, he can only swing back and forth like a swing to try to approach Zhang Yanhang, but unfortunately, the rope is too short and Zhang Yanhang is floating outside the window. The middle-aged ghost exerted all his strength, almost breaking his neck, but still couldn't get close to Zhang Yanhang.

Looking at those bloodshot eyes, seemingly bulging out of their sockets, Zhang Yanhang thinks aside from being a hanging ghost, he might also have become an Earth-bound Spirit due to his deep resentment towards this office, unable to leave it or the hanging rope, resulting in a comically futile swinging back and forth yet unable to reach Zhang Yanhang.