Wu Yu could not resist a closer look.

Of course, the closer he got, the more realistic this skull looked. Although it was pitch-black, like ink, the bone definitions were basically the same as an ordinary skull's. It did not look like it was carved or forged, but rather a natural object.

The Bloody Yan Cave was about the same size as the Immortal City of Northern Frost, while the Flaming Devil Cave was about 10 times the size of the Bloody Yan Cave, and was close to the scale of the Dark North Capital. This huge skull castle was a disconcerting sight for Wu Yu.

There were many strange and fascinating places in the world, many more than Wu Yu had imagined.

The Taigu Immortal Path, the Alternate World, the Infernal Inferno, etc. These places were probably plentiful throughout the Jambu Realm, as well as the legacies of ancient martial cultivators, the treasure hoards of vanquished nations of history. From the records, many had yet to be rediscovered.

Although this Flaming Devil Cave was quite fascinating, from his experience at the Bloody Yan Cave, he knew it could be fatal for him to barge in. Therefore, Wu Yu observed for a while, then prepared to move on. He skirted the Flaming Devil Cave and continued downwards.

The orifices of the Flaming Devil Cave skull were entrances. He could see many experts of the Ghostly Yan Tribe guarding them. It would probably be much harder to enter compared to the Bloody Yan Cave. This was the most important base of the Ghostly Yan Tribe, and probably had countless Defensive Spirit Designs and large scale killing formations set up everywhere.

"I wonder just how powerful Ye Xixi's father, the Flaming Devil Cave's Holy Master, is. Ghostly cultivators can become ghostly immortals when they reach the limit. I wonder if he is slated to reach that."

Wu Yu was a little curious.

These were the most elite in the Jambu Realm.

Luo Pin had already reached that level.

Immortal beasts had naturally already reached immortalhood.

For demons, the situation was a little less straightforward. After experiencing their crises, some demons descended to the 10,000 Levels of Hell, where they would become demon immortals. They might also rise to the Sky Palace and become true immortal beasts through a thorough metamorphosis.

Immortal beasts in the mortal realm and immortal beasts in the Sky Palace were on completely different levels. Immortal beasts in the mortal realm came from bloodlines, and their numbers were few.

Immortals, ghostly immortals, demon immortals, and immortal beasts. All of them were the ultimate forms that mortal martial cultivators, ghostly cultivators, and demons could reach in this life, and that was Wu Yu's goal!

"After passing the Flaming Devil Cave, there will probably be no more Ghostly Yan Tribe members. At such magma temperatures, Ghostly Yan Tribe members not at the Dao Querying Realm cannot possibly endure."

Heading down, he indeed encountered no more spirit designs. The Ghostly Yan Tribe had no need to set defenses here. Their only enemy was the Yan Huang Tribe, and this was the backyard of their major camp.

For Wu Yu, this was also hard to bear. While withstanding it with his Invincible Vajra Body, he even had to supplement it with his Violet Kingdom Primordial Energy to make things a little more comfortable.

He wanted to see just how deep the Infernal Inferno went, and how hot it would run. He wanted to know his own limits.

Or what lay at the end of the Infernal Inferno!

With an attitude of challenging his limits, he continued to go deeper, and this was a process much like ascending to heaven. At the end, there could not be any Ghostly Yan Tribe members. It was a deep sea of magma. Besides magma, all that could endure were the rocks. After years of being imbued with the fiery spiritual qi of the magma, even the ordinary rocks would have spiritual marks.

Deeper! Deeper!

Where the limit was, there Wu Yu would go.

He would not turn back before his Invincible Vajra Body was at its limit and he would lose his life if he went deeper.

Frequently, Wu Yu had to hold on as though he were trying to absorb the Elixir of Fire Spirit.

His indomitable will was the strongest pillar of strength and weapon that he had.

As he continued downwards, Wu Yu himself lost track of how far he had progressed, and how much time had passed. But there seemed to be no end to the Infernal Inferno.

It seemed like the Ghostly Yan Tribe only lived in the middle of the Infernal Inferno, and not at the deep end. Wu Yu could not ascertain how far down he was. Perhaps he was only in the middle now.

A few days passed, and there was nothing around him. Not even demons or Spirits of the Universe were present. A completely deathly, empty view, with nothing but roiling magma.

At this time, Wu Yu was basically hard pressed to hold on. He knew that he might not make it to the end.

"I wonder if others have gone deeper than I have." He paused to rest, surveying his surroundings with the Eyes of Fire and Gold.

After merging with the Elixir of Fire Spirit, his Eyes of Fire and Gold's penetrative vision had been enhanced, especially their heat sensitivity. From his position, he discovered a slight disturbance in a certain direction as he scanned. There was a region that seemed especially hot, and exceptional compared to its vicinity.

"Elixir of Fire Spirit?" Wu Yu had absorbed an Elixir of Fire Spirit before, and so he was quite sensitive to it still. From his position, he very quickly sensed that there was something similar to his Eyes of Fire and Gold over there.

It might very well be an Elixir of Fire Spirit.

Although his Paradise's Fiery Demise had already been completed, an Elixir of Fire Spirit was still very useful for Wu Yu. After a period of observation, he decided to forgo his descent and changed direction to move towards that region he had spotted.

He flew very quickly on the Somersault Cloud. The closer he got, the stronger the feeling in his eyes. When he met the Elixir of Fire Spirit, his eyes seemed to exude joy, as though they had found their kind.

However, the Elixir of Fire Spirit was exceptionally mischievous. It zoomed around within the magma as though a fish in the deep sea.

Whoosh, whoosh, whoosh!

Wu Yu had heard the voice already, and sped over. As expected, he saw the Elixir of Fire Spirit, a bunch of red liquid, playfully zipping about. From its volume, it looked more than the last bit of Elixir of Fire Spirit that Wu Yu had the other time, perhaps close to twice the amount.

"Hu!"

Wu Yu charged up with the Somersault Cloud's great speed.

However, in the depths of boiling magma, his speed was severely affected, and the Elixir of Fire Spirit fled quickly upon seeing him. This chase would not be easy.

Luckily, there was no one contending with him for it this time.

The Elixir of Fire Spirit continued to flit here and there. Anyone else would have been thrown off long ago, but Wu Yu was different. His Eyes of Fire and Gold were locked on to it. Although the spirit was quick, he was gaining on it. The only problem was that the Elixir of Fire Spirit was moving downwards diagonally, which meant that Wu Yu would have to go deeper into the Infernal Inferno to chase it. Wu Yu would not care about this at this time. He gritted his teeth and endured the heat, keeping up the chase!

Boom!

Wu Yu's advance through the magma stirred it up!

The deep sea had been churned by Wu Yu!

This Elixir of Fire Spirit was too agile. A few times, Wu Yu neared it, but was unable to lock it down with the Dark North Royal Obelisk! The key was that it was taking a strange route. The further it went, the hotter the temperature that Wu Yu's body had to bear. His skin was already charred. Although it continued to regenerate, at some point, it would burn faster than it could regenerate. At that time, Wu Yu would be in trouble. This forced Wu Yu's speed to decrease as well!

He was quite depressed.

"The meat in my jaws is about to escape?"

He was not content with that. He continued to pour on the speed with the Somersault Cloud!

RUMBLE!

At this time, a huge sound boomed out with a wave of magma.

Chase! Chase!

On this chase, Wu Yu ignored his surroundings. Not many people came to such depths of the Infernal Inferno. Besides, this place was extremely vast, and therefore no one had been to this area before.

Suddenly, he felt the heat break past his limit, and his speed was again discounted. The Elixir of Fire Spirit seized this opportunity to slip away before him, and seemed to have vanished.

"Impossible!" Wu Yu sped forth, struggling through the pain he felt. He saw that the Elixir of Fire Spirit had indeed disappeared, but there was a strange object before him. It looked like a huge, glass bottle mouth, circular in shape. The Elixir of Fire Spirit had entered this area.

A glass bottle in the depths of the Infernal Inferno?

Although this glass bottle was transparent, what was inside was unclear. It seemed to be filled with magma, and the opening of the bottle indicated that it was something special.

Although the Elixir of Fire Spirit had entered the bottle, Wu Yu was in no hurry to pursue. Instead, he circled the glass bottle, and discovered that it was actually a lamp, a little like the one that mortals put kerosene into. Although transparent, one could not see the contents clearly. He could see many cracks. This glass lamp had been broken before, and he could feel waves of heat emanating from these cracks, as though something incomparably hot lied within!

As he recalled the Elixir of Fire Spirit that entered, Wu Yu suddenly had a flash of inspiration. An idea flitted past his brain, and Ming Long was first to speak it out. "This wouldn't be the vessel that the Elixir of Fire Spirit comes from, would it? Something that came from Sky Palace...? Such a huge glass lamp should be from Sky Palace. Could there be a lot more Elixirs of Fire Spirit within? The Elixir of Fire Spirit does not originally belong to the mortal realm. Could it have come from this broken glass lamp?"

This notion was a revolutionary thought. Wu Yu was shaken as well. Of course, he knew that such places often came with their dangers. Therefore, he was still very cautious as he approached the glass lamp.

Although some places were cracked, there was not a large enough opening for him to enter.