As Hu San chanted incantations and tapped his finger on the crystal ball several times, a layer of colorful crystal light suddenly bloomed on the surface of the crystal ball, enveloping Han Li and the others.

After the crystal light flickered slightly, Han Li and the others disappeared from their original location, and even their aura was completely concealed.

"Is this an illusion technique that Fellow Daoist Hu San is using?" Han Li asked doubtfully.

"You could say that. This layer of crystal light cannot touch the perception restrictions, otherwise, our tracks will be immediately revealed. We don't have much time, let's act quickly." Hu San nodded and urged.

With that said, the group swaggered to the base of the black city wall under the cover of this layer of crystal light.

As expected, they didn't attract the slightest attention from the surroundings. Those You Nu guards stood there stiffly, without even a ripple in their eyes.

Seeing this, Han Li finally felt a little relieved.

"Is this place about right?" Hu San asked.

"Hold on, I need to set things up."

While speaking, Shi Chuan Kong began to take out formation disks and Shattered Inkstones, arranging them on the ground.

"You can use this thing to set up a formation? I originally thought you bought it for that monster core." Han Li said with a slight start.

"Setting up a spatial formation requires convenient terrain and resources, so it's better to use what's available on the spot. Anyway, with Fellow Daoist Mo Guang here, I can teach him how to activate it." Shi Chuan Kong said with a smile.

With that, he continued to work diligently on the arrangements.

Han Li carefully observed from the side, noticing that the formation Shi Chuan Kong was setting up was very complex, somewhat similar to a teleportation formation, but with obvious differences. With his eyesight, he couldn't see too many clues.

"Brother Shi, are you done yet? My Shadow Illusion Crystal can't last much longer..." After a while, Hu San urged anxiously.

"Alright, everyone, stand in the formation." Shi Chuan Kong embedded the last formation disk into the formation, wiped his forehead, and stood up to say.

Hearing this, Han Li and the others immediately moved into the formation, a small circle that was just enough for the five of them to stand.

"It's not difficult to activate. In a moment, you should try to restrain your aura as much as possible, and I will conceal the fluctuations of the city wall formation." After listening to Shi Chuan Kong's method of activating the formation, Mo Guang nodded and said.

Then, he raised a finger, and immediately, rolling Shattered Qi flowed out from the tip of his finger, rotating like wisps of black smoke, enveloping all five of them.

Immediately afterward, a chanting sound came from Mo Guang's mouth, and circles of spatial fluctuations immediately emerged from the formation beneath their feet, but were blocked by the surrounding black wall of Shattered Qi, preventing any leakage.

"Go." With a soft shout, Hu San's illusion crystal light exploded at the same time.

The figures of the people in the formation twisted at the same time and disappeared.

On the city wall, a You Nu's eyelid twitched, and he looked down at the base of the city wall with a sense of unease, only to see a whirlwind seeming to have risen there, stirring up a patch of gray-brown dust on the ground.

He quickly released his spiritual sense to sweep across it, but found nothing unusual.

Moreover, the restrictive formation on the city wall didn't show any fluctuations. He shook his head, his indifferent face devoid of any expression, and returned to his original appearance.

On the other side, on a small path paved with blue-gray bricks, the figures of Han Li and the others emerged, and then their figures flashed, silently flashing towards the city.

Perhaps because the Three Regions Alliance was being held, the Hundred Treasure District seemed even more deserted. The buildings in the city were generally not high, only some high towers like bunkers stood tall, and each of them was guarded by a You Nu in armor.

In some streets and alleys of the city, one could still see teams of patrolling You Nu shuttling back and forth, and among the leaders, one could occasionally see some who were comparable to True Immortal cultivators.

"The defenses in this Hundred Treasure District are obviously stricter, so we must be more careful." Shi Chuan Kong said, looking around.

"I observed carefully just now, and the situation in this Hundred Treasure District is quite different from what is marked on the map. The positions of many patrol towers are not marked." Mo Guang said in a deep voice.

"That's not surprising. This map is probably an earlier version before the entire Asura City was under martial law. Naturally, any changes in the city afterward will not be shown on it, as long as the road distribution in the Hundred Treasure District is correct." Han Li shook his head and said.

"There are no abnormalities in the roads. There are three roads to the border with the Luo Sheng District, two of which lead to the city gates, and the other leads to a corner tower in the northwest direction." Mo Guang said after thinking for a moment.

"Then let's go to the corner tower first. The city gate is probably the same as before, with Grand Luo Realm cultivators stationed there." Han Li said thoughtfully.

The others had no objections to this.

After agreeing, they avoided the patrol towers and patrolling You Nu in the city and carefully traveled through the Hundred Treasure District.

After traveling a distance within the Hundred Treasure District, the number of patrolling You Nu in the city not only didn't decrease, but increased somewhat. However, the number of patrol towers also increased a lot, and each You Nu in armor closely patrolled above at all times.

The Hundred Treasure District was simply five steps for a post and ten steps for a sentry.

Even though Han Li and the other five were all highly cultivated, they had to be highly vigilant and proceed cautiously in such a situation.

In the blink of an eye, half an hour passed, and the five finally arrived in the central area of the Hundred Treasure District and hid behind a tall building to rest briefly.

Han Li looked around, raising his eyebrows slightly.

He could clearly feel that there was a sudden increase in bone-chilling coldness in the air here, and a layer of white frost faintly condensed on the nearby ground and walls.

Ordinary buildings could no longer be seen here. On both sides of the road were black, tall fortress-like buildings, and they were connected to each other, forming a continuous group of fortresses.

Several huge chimneys stood out from the fortress group, and rolling gray smoke poured out from them from time to time, looking like some kind of large workshop.

There were especially many guards near this fortress group, and streaks of light flew over from time to time in the air, patrolling everything below.

"There are so many guards here, it seems that this building complex is not simple. Perhaps it hides some kind of secret of the Nine Serenities Race." Hu San looked at the fortress group in front of him, his eyes shining slightly, and communicated with the other four through voice transmission.

"What's in here has nothing to do with us. Finding the Shattered Cleansing Pool is the top priority. Hu San, the situation is different now than before, don't cause any unnecessary trouble." Shi Chuan Kong's expression tightened, and he immediately warned.

"I know, don't worry." Hu San said with a faint smile.

Shi Chuan Kong was still a little uneasy, staring at Hu San, as if afraid that he would cause trouble.

Han Li glanced at the two of them, then turned his gaze and looked at the black fortresses around him. With a thought, a wisp of spiritual sense quietly penetrated into them.

As soon as his spiritual sense penetrated a little into the fortress wall, it was immediately and unceremoniously bounced back by an invisible force.

A look of surprise flashed in Han Li's eyes, and he quickly withdrew his spiritual sense, without continuing to forcefully probe.

"Boy, do you want to know what they're doing in here?" At this moment, Shi Qing Hou's voice sounded in Han Li's heart again.

"It seems you know?" Han Li raised his eyebrows and asked through voice transmission.

"What's laid out in this wall is the Nine Serenities Great Hidden Mysterious Restriction. Although this technique is a secret restriction passed down by the Nine Serenities Race, it's not difficult to crack. I'll pass on the cracking method to you, and you can see for yourself." Shi Qing Hou didn't answer Han Li's question and said to himself.

Then, a stream of consciousness was transmitted to Han Li's mind, which was a mysterious method of cracking the restriction.

"Why are you passing on this secret technique to me, to let me investigate the situation inside?" Han Li obtained the secret technique, but didn't show any joy. He frowned slightly and asked through voice transmission.

But at this moment, Shi Qing Hou fell silent again, seemingly not intending to respond.

Han Li's eyes darkened, and after a slight hesitation, he still decided to release a wisp of spiritual sense and penetrate into the wall again.

An invisible force immediately emerged from the wall, blocking the progress of his spiritual sense.

His eyes flickered slightly, and then he activated the restriction cracking method.

The originally tough restriction force quickly became soft, and then merged with his spiritual sense.

Immediately afterward, his spiritual sense "poofed" and easily penetrated in, seeing the situation inside.

Han Li's eyes flashed slightly, but then he recovered.

The fortress he was investigating contained a huge pool, about twenty to thirty zhang in size. The pool was filled with grayish-white liquid, and it was currently boiling violently as if it had been heated.

Four black iron cages were submerged in the pool, holding two Gray Realm alien beasts and two people with bull horns on their heads. It was unknown what race they were.

The two Gray beasts let out miserable screams, struggling desperately in the iron cages, wanting to break out, but the iron cages were extremely strong, firmly holding the two beasts inside.

The other two horned aliens didn't struggle or scream. Their bodies seemed to have become stiff, lying straight in the cages, and only their eyes occasionally moved, showing that they were still alive, but their expressions were also extremely dull.

These two aliens seemed to have been soaked in the pool for too long, and their bodies were grayish-white, looking a little strange.

In addition to this, there were two You Nu standing by the pool, closely observing the situation in the pool.

Han Li was surprised, but he didn't look at this place much. He quickly spread out forward and entered the next fortress.

There was no pool in this fortress, but a huge furnace stood, with rolling gray flames burning beneath it, but it didn't emit the slightest scorching heat. Instead, it emitted bursts of bone-chilling cold.

And in the furnace, several grayish-white Gray Realm aliens or Gray beasts were hanging.

Streams of gray light radiated from the furnace, quickly merging into the bodies of these aliens and Gray beasts.

The bodies of these aliens and Gray beasts quickly became swollen, as if they were being inflated, and strange patterns appeared on their skin.

Han Li's spiritual sense stayed here for a while, and continued to spread deeper, and in the blink of an eye, he checked more than a dozen black fortresses. Each fortress had a unique method of body tempering, either boiling in water, burning with fire, or quenching with poison.

Those Gray beasts and aliens were quenched in these fortresses in turn, and their bodies continued to change, transforming into various human and beast-shaped monsters.

The aura of these monsters was much larger than before, but they had lost their minds and turned into emotionless puppets, locked in huge iron cages and piled in the last fortress.