The others shared a look. Despite their reluctance, they had no choice but to follow when Lu Yun was so self-assured.
“Do you still plan to make Lu Yun one of your own?” Glancing at his brother, Qing Han transmitted silently with a sneer and a sniff.
Qing Hongchen’s gaze flickered rapidly. “A talented man is a man I can use!”
“Ha, but can you keep him under control?” With a huff, Qing Han closed his eyes and trailed after Lu Yun.
Chilling wind swept past their ears when they set foot into the formation, like something whispering in their ears. Shudders ran down their spines. Only then did they understand what had happened to that city lord before his death.
“Master!” someone yelled, followed quickly by the sound of a head falling to the ground.
“What? Is Qing Hongchen dead?” Qing Han tensed. He wanted to open his eyes, but Lu Yun’s words came to his mind and gave him pause. He barely suppressed his curiosity and kept walking forward with his eyes closed.
“No! Don’t kill me!” Another yell, and another thud of a head hitting the ground.
“Li Youcai is dead?” Mo Yi shook slightly, but her expression remained calm and unaffected.
Finally, the group reached their destination and everyone opened their eyes.
“Lu Yun?” said the Skyriver City Lord in disbelief when he saw Lu Yun, alive and well. “Aren’t you dead?”
“You’re alive, Qing Han!” Qing Hongchen was surprised to see his brother, too.
“I thought you were dead too,” Qing Han responded coolly.
Mo Yi remained silent. Seeing Li Youcai made her realize what was going on.
“The Cloudlake City Lord is gone,” someone counted.
“He’s the only one who actually died,” Qing Hongchen pronounced in a cool voice. “He most likely opened his eyes when he heard someone die, which made him the one casualty.”
Lu Yun pursed his lips without a word. Ge Long had scared away the strongest beings in the formation, leaving only a few weaklings, yet someone had still died at their hands.
Formation Thirteenth looked back thoughtfully in the direction they came from. “This is indeed the eye of the formation,” he said, pointing at a light violet shoot of grass. “If we go down there, we’ll be able to enter the place guarded by the formation without triggering the defenses.”
Lu Yun nodded. That shoot of grass disrupted the layout, leaving a weak point in the Duality of Dragon and Tiger.
“Dig here, and we’ll be able to enter the great mound.” Lu Yun’s breath quickened. A great burial mound! Buried beneath it was someone with unimaginable power! Their unresolved grievances were strong enough that they’d turned a mere burial mound into an enormous mountain! His blood boiled with excitement just thinking about raiding a tomb like this.
“Dig?” the Skyriver city lord scoffed. “You’re trash who couldn’t cultivate before, alright. We cultivators have mastered the techniques of the five elements. An earth-bending combat art will get us underground without digging.”
Lu Yun shrugged and gestured at him to go on.
“You can’t do that.” Formation Thirteenth shook his head. “There are always strange formations in ancient tombs that can negate a cultivator’s consciousness, or even their combat arts. Digging a path down is the safest way to go.”
The city lord’s face turned blue, but he wasn’t going to argue with the formation master.
“Stop after digging a hundred and thirty-five yards, seven feet, and three inches,” Lu Yun commanded in a low voice. “No more, no less!”
“Move it!” ordered Qing Hongchen.
Li Youcai wasn’t going to get his hands dirty. He sat down on the ground and took out a piece of grilled meat, leisurely enjoying his snack. That left the four remaining city lords and Qing Han as the group’s laborers.
Sword energy slashed through the air and cut into the soil, creating a small tunnel that led directly underneath the ground.
“A hundred and thirty-five yards, seven feet, and three inches. Done!” After twenty-odd breaths of time, the Skyriver city lord’s voice echoed from underground. “There’s nothing here.”
“That’s because you’re a fool.” Lu Yun sniffed and turned to Mo Yi. “Stay here. If anything happens underground, come help us.”
“Alright.” She nodded.
Qing Hongchen’s face darkened. “She’s not coming with us?”
“If she does, we’re all dead.” Lu Yun shook his head slightly. “There are great dangers underground, so we need someone outside to coordinate with us.”
“I—I’ll stay with her!” Li Youcai volunteered himself.
“No, we only need Mo Yi,” Lu Yun responded as he entered the tunnel, a cold smile tugging his lips. I’ll take care of all of you in the tomb!
“Come on,” Qing Han sighed, then entered the tunnel in a flash.
“You—” Li Youcai stammered to Mo Yi before following them, “you must watch this tunnel well. Don’t let anyone destroy it!”
She couldn’t be bothered to respond.
“Oh, heavens above!” An excited exclamation travelled from the end of the tunnel. “There are so many immortal weapons and treasures here. What’s that? An immortal pill!”
“There really are treasures here!” Li Youcai was already fantasizing about his potential loot. He picked up speed as he rushed down the tunnel.
“A teleportation formation.” Yuying’s experience greatly enriched Lu Yun’s knowledge, so he now knew there was such a thing in the world of immortals.
This burial mound is much more powerful than the ancient tomb Yuying was buried in, but its tomb odor has aired out. That means the coffin inside has definitely been tampered with, and the general layout of the mound has changed.
Yuying’s tomb had been broken into by those from the Exalted Immortal Sect, but they’d failed to pry open her coffin so the odor of her tomb remained. This burial mound was another story. It was clear that someone had opened the coffin five thousand years ago, or even earlier.
What Lu Yun was after, though, was the Formation Orb that Mo Yi had told him about. Since the formations outside the mountain were still standing, the Formation Orb must still be here. He didn’t care if the coffin had been tampered with.
Those at the end of the tunnel had disappeared.
“This is the Sevenfold Layout, the seven parts of which form a teleportation formation.” The intricate layout was buried underground. If Lu Yun hadn’t been paying close attention to the landscape outside, he wouldn’t have noticed it.
His precise calculations placed the tunnel straight at the Sevenfold Layout. Prior to stepping into the formation, he memorized the arrangement of the feng shui.
A swirl of flashing images later, an extravagant palace appeared in front of him. A plethora of items and treasures were scattered all over the place. There were also the utmost treasures of immortal dao that Yuying remembered, but could never get her hands on.
Lying at the center of the main hall was an enormous bronze outer-coffin. 
“A bronze outer-coffin!” Lu Yun felt his skin crawl. There were two things tomb raiders never wanted to encounter: A netherwood coffin, and a bronze outer-coffin!
1. Wondering why sarcophagus wasn’t used this time? Because it’s an outer-coffin specifically made of stone. ;)