The miniature radar also had a thermal imaging function, which made it extremely sensitive to the presence of life forms.

After activating the radar, Tang Wulin only had to continuously inject his soul power into it to maintain the three-dimensional image in his mind. Dilapidated factories and equipment lay all around him, and it was a very barren place.

This was a search mission, so all he had to do to complete it was search through his designated section.

Tang Wulin hurried along, and at the same time, he was controlling his soul power to close off his pores and conceal his aura. He was also treading very lightly and making about as little sound as a prowling cat in the night.

This type of aura concealment skill was something that he'd learned from Old Demon Scourge on the demonic island. The most important element of infiltration was to avoid being discovered by enemies. Old Demon Scourge's aura concealment skill was very useful as not only was it able to conceal one's aura, it also taught one how to fuse their soul power with destructive energy, thereby lowering their body temperature to avoid detection from thermal imaging devices.

Tang Wulin was putting this skill to extremely good use, so even if someone were aiming a sensory device at him right now, they wouldn't be able to detect him as he'd completely sealed off his aura and soul power, while also lowering his body temperature to match his surroundings.

Old Demon Scourge had told him that everyone only lived once, so regardless of what situation he was in, he had to do everything he could to minimize his risk of being harmed. If he were to make a mistake due to complacency, then he may not have the opportunity to regret his mistake as he could already be dead.

These lessons had been drilled into Tang Wulin's mind through the torment inflicted on him by the old demons. As such, he was doing everything he could to blend into the night while advancing through the abandoned industrial area. Even the energy fluctuations emanating from the miniature radar on his badge had been concealed by him using his soul power.

Tang Wulin was the fastest among Shrek’s Seven Monsters to master his aura concealment skill as he possessed the most spiritual power. His Spirit Abyss realm spiritual power made it a lot easier for him to master all aspects of the skill than it was for everyone else.

Soon, Tang Wulin had searched through most of his section without making any discoveries. Perhaps it was due to the presence of harmful substances in the area, but there weren't even any insects or rodents around. This was a truly dead and desolate place.

"The innermost section has been completely searched with no discoveries." Purple One's voice sounded in his earpiece.

"The eastern section has been completely searched with no discoveries." Next to report his findings, or lack thereof, was Yellow One.

Tang Wulin pressed down on his communicator, and said, "The western area has been completely searched with no discoveries."

Yellow Two's voice then quickly rang out. "The search through the southern area is still ongoing."

Purple One instructed, "Yellow One, Yellow Three, you two head to the southern area to meet up with Yellow Two and Yellow Four. I'll come to join all of you after searching through the northern section."

"Yes!"

As the leader of the team, Purple One naturally took on the biggest workload. This was a rule in the Battle Hall, and even if it hadn't been in place, everyone automatically carried it out anyway.

Tang Wulin sped toward the southern section, and he quickly found Yellow Two and Yellow Four using the positioning function of his yellow badge. Yellow One had arrived there ahead of him as he was an agility-type Soul Master.

"Looks like there's nothing here," Yellow One said in a disappointed manner.

According to the rules, they had to find some leads to complete the mission. Otherwise, they'd only receive a third of the reward.

Yellow Two smiled, and said, "Hopefully, Purple One can bring us some good news."

Tang Wulin merely nodded in response.

Beneath his mask, his brows were tightly furrowed. He hadn't found anything in his search, but he still couldn't shake the feeling that something was off. He had fought evil Soul Masters on many occasions, and with his sharp senses, he could feel that there was an indescribable sense of oppression in this area that made him very uncomfortable.

Not long after that, a figure quickly sped toward them. Tang Wulin and the other yellow agents reflexively adopted defensive stances while checking their badges.

It was Purple One.

Purple One arrived before them, and said, "This place is completely empty, and my thermal imaging sensor couldn't pick up anything, either."

Yellow One asked, "What do we do then? Was this a pointless trip?"

Purple One paused momentarily before replying, "It appears to be so. After launching such a large-scale terrorist attack, it only makes sense that all of the evil Soul Masters would've fled Heaven Dou City already. This place has already been searched by the military once before, and they didn't find anything here, either."

Yellow Two heaved a resigned sigh while Yellow Four and Tang Wulin remained silent.

Purple One continued, "Alright, let's get out of here."

There was no point in staying here any longer considering they hadn't discovered any leads. Their agent badges had very reliable search functions, and if the miniature radars couldn't pick up anything, then they wouldn't be able to, either. As such, they could only go back.

"Waah...." Right at this moment, a burst of low sobbing suddenly rang out.

All five of them immediately turned toward the direction that the sobbing was coming from. To hear sobbing in the pitch-black night within an abandoned industrial site like this was truly a harrowing experience, and all of the hairs on the backs of their necks immediately stood up on end.

Tang Wulin was the calmest among them. He'd seen much more unsettling things on the demonic island.

"Who's there?" Purple One yelled as he activated his miniature radar. As a purple agent, his radar covered a range with a radius in excess of 300 meters, but much to his surprise, it detected zero life forms.

"Waah..." The sobbing continued.

Tang Wulin's brows furrowed slightly as he vaguely recalled something.

All of a sudden, loud sobs erupted all around them, and it was as if countless people were crying at the same time. The sobs echoed throughout the area, and more unsettling scenes ensued. A series of ghostly figures appeared, and the dilapidated equipment around them began to sway slightly as if they'd all sprung to life.

"Be careful, everyone!" Purple One cautioned as he released his martial soul. Seven soul rings emerged from beneath his feet, revealing him to be a Soul Sage.

It was undoubtedly the case that the Battle Hall was extremely careful when assigning missions as every single agent is extremely precious to the Battle Hall. As such, even a small search team like this one was being led by a seven-ring two-word battle armor master. With a suit of two-word battle armor, a seven-ring Soul Sage was comparable in power to a normal Titled Douluo, and that was more than enough to take care of most dangerous circumstances.

Yellow One, Yellow Two, and Yellow Four also released their martial souls; they were all five-ring Soul Kings. Yellow Two stood at the very center of the formation while the other four members of the group surrounded her with their backs facing her.

Tang Wulin also released his soul rings, and strangely enough, they consisted of two yellows and three purples, which was roughly the same as the soul rings of the other yellow agents.

He was using his disguise skill, or more specifically, his soul ring disguise skill! This had been taught to him by Old Demon Nightmare.

The most direct way for Soul Masters to ascertain one another's powers would be by inspecting the number of soul rings one had, as well as the color combinations. Different colors indicated different ages, and on the flipside, soul rings could also expose a Soul Master's power level for everyone to see.

As such, Old Demon Nightmare taught Tang Wulin a disguise skill that drew upon a combination of his spiritual power and destructive energy in order to distort the vision of others. Basically, he was distorting the light waves radiating from his soul rings, thereby making them appear as if they were different colors to the beholder.

This disguise skill didn't directly make him stronger, but it was very practical. Especially after Tang Wulin attained that one-of-a-kind greenish-golden soul ring, the disguise skill became even more important to him.

At the very least, he appeared to be no different from an ordinary Soul Master of his cultivation rank.

"Waah..., waah..., waah..." The sobs were becoming even more unsettling, and chills were running down everyone's spines.