The so-called Yin Soldiers were actually some remnant souls of war.
This underground world was a Yin land, a place of extremely special conditions.
Therefore, these remnant souls had been preserved here all this time, never dispersing.
"What are those?!"
Wen Zi watched the cavalries shrouded in the Yin mist, her small face pale with fear.
Because those cavalrymen had deathly pale faces, vacant stares, and were brimming with murderous aura — they were utterly terrifying.
"So scary!"
The dozens of students were also frightened into pallor, pressing closely behind Ye Yunfei.
"These are ghosts.
Weren't you just asking if there were ghosts here?
Now you see them."
Ye Yunfei laughed.
"Are these... really ghosts?"
Wen Zi was both scared and fascinated, her eyes not blinking as she stared at the cavalry.
"Truly astonishing!"
The dozens of students all murmured in awe.
Although those cavalrymen looked immensely frightening, they weren't overly afraid with Ye Yunfei present.
"Earth Flame should be effective."
Ye Yunfei flicked his finger.
A vermilion flame flew from his fingertip — it was precisely the Earth Flame.
Whoosh…
Immediately, that Earth Flame blazed vigorously, transforming in an instant into a crimson sea of fire that encircled Ye Yunfei, Wen Zi, and the dozens of students on all sides.
The cavalry had originally been charging towards Ye Yunfei's group but now all came to a halt. The two sides stood facing off.
The Earth Flame was a variant fire of Heaven and Earth, furthermore one belonging to the Yang attribute.
It happened to restrain these Yin Soldiers perfectly.
This was what was called 'All things under heaven, one thing curbs another.'
Ye Yunfei willed it, unleashed his Heavenly Soul Sword, and slashed towards the Yin Soldiers.
These Yin Soldiers were, in essence, a mass of remnant souls.
And the Heavenly Soul Sword was formed by condensing Soul Power with sword intent.
Using the Heavenly Soul Sword to deal with these Yin Soldiers was highly effective.
*Clang! Clang! Clang!…*
The Heavenly Soul Sword moved with extreme speed, continuously striking at that cavalry.
Soon, it exterminated the entire troop.
What was marvelous was that after those cavalrymen died, their bodies transformed into wisps of black Yin Qi, leaving nothing behind except heaps of armor scattered on the ground.
Next, Ye Yunfei led Wen Zi and the dozens of students into the palace ahead.
"So many Ancient Demon Race corpses!"
The moment he entered the palace, Ye Yunfei couldn't help but exclaim.
The palace was filled with stone coffins.
Each stone coffin released vast amounts of demonic aura, forming a dense layer of demonic mist that flowed like water, permeating the great hall.
Under Ye Yunfei's Soul Power perception, he instantly knew that within each stone coffin lay a corpse of the Ancient Demon Race.
Previously, when Ye Yunfei was in the Eastern Region participating in Hudao Academy's entrance assessment and entered that ancient battlefield, he had obtained ten Ancient Demon Race corpses.
Thus, he was quite familiar with them.
"So many coffins!"
Wen Zi and the dozens of students, looking at the densely packed stone coffins within the palace, couldn't help but feel their scalps tingle.
"Do not disturb those stone coffins."
Ye Yunfei cautioned.
He knew that these Ancient Demon Race beings might still harbor residual consciousness; activating them would be extremely dangerous.
"Master, you can use these Ancient Demon Race corpses to cultivate your Heavenly Demon Blood-Refining Body Art,"
Hu Miao said via Sound Transmission.
"Correct.
We definitely can't miss these Ancient Demon Race corpses."
Ye Yunfei nodded.
The demonic bodies of the Ancient Demon Race were very special. Even after death, the Bloodline Essence within their bodies could be preserved for a long time.
Especially within this underground world arranged as a Yin land, the Bloodline Essence within these Ancient Demon Race bodies had barely diminished.
Ye Yunfei walked to the side of one stone coffin and was just about to reach out to collect it when—
*Screech! Screech!…*
A large flock of pitch-black Ghost Crows suddenly appeared, swooping towards Ye Yunfei like a dark cloud.
With this many Ghost Crows attacking simultaneously, even Ye Yunfei felt a bit of a headache.
Thus, Ye Yunfei had no choice but to retreat.
The flock of Ghost Crows did not pursue Ye Yunfei. Instead, they settled upon the stone coffin.
They seemed to be guarding the coffin!
"Let it be.
Let's go check the other palaces first."
Ye Yunfei said.
And so, Ye Yunfei led Wen Zi and the dozens of students to investigate several palaces in succession.
The situation in each palace was the same: filled with densely packed stone coffins, each containing a corpse of the Ancient Demon Race.
Moreover, every time Ye Yunfei tried to make a move to collect a stone coffin, large numbers of Ghost Crows would emerge to protect them.
"It seems this underground mausoleum was definitely built by the Ancient Demon Race,"
Ye Yunfei pondered inwardly.
In the past, when the Extraterritorial Invaders invaded the Tianxuan Continent, the Ancient Demon Race was one of those invaders.
Afterwards, they fought a great war.
The inhabitants of the Tianxuan Continent united, driving back the Extraterritorial Invaders.
In that battle, the Ancient Demon Race suffered heavy casualties.
Thus, even to this day, many Ancient Demon Race corpses were still scattered across the Tianxuan Continent.
Never did he imagine this Crystal Mine Minor World would also conceal so many Ancient Demon Race corpses.
"Master, look, the demonic aura is most concentrated around that palace at the very center,"
Hu Miao suddenly said.
"Indeed."
Ye Yunfei's gaze also turned towards the palace in the very center.
That palace was noticeably larger in size.
Moreover, the demonic aura was denser, swirling like billowing black clouds.
At times, faint sounds of ghostly wails and wolves' howls drifted from it.
A fearsome pressure of demonic power radiated from within that palace, spreading in all directions.
"This place is too dangerous.
What's more, even more perilous events might unfold next.
For now, I will teleport you all to a safe location.
Rest assured, I will bring you all out of here safely."
After some thought, Ye Yunfei said to Wen Zi and the dozens of students.
He intended to explore the palace at the very center. However, bringing Wen Zi and these students along was far too dangerous.
"Teleport us to a safe place?"
Wen Zi and the dozen-odd students were taken aback.
"Yes.
Just trust me."
Ye Yunfei nodded.
"Alright."
Wen Zi and the students all nodded.
They naturally trusted Ye Yunfei. Moreover, they were well aware that given their own strength, following Ye Yunfei would indeed add to his burden.
Ye Yunfei waved his hand, teleporting Wen Zi and all the students into the Phantom Tower.
Then, he lifted his foot and walked towards the palace at the very center.
Without Wen Zi and the students following him, Ye Yunfei instantly felt much more at ease.
"Ye Yunfei, let me come out too.
This place, for me, is like a fish in water."
Suddenly, Huang Shang materialized beside Ye Yunfei.
"Alright."
Ye Yunfei nodded.
Indeed, Huang Shang was currently a ghost cultivator. This kind of ghostly, Yin-filled place was most suitable for him.