Generally speaking, even if a monk has the opportunity to enter this underground cave, I am afraid that there is not the slightest chance to discover that underground cave, there is such a strange treasure, if the existence that enters it does not master a certain amount of spatial power, it will not sense the fluctuation of spatial power in this huge mustard stone at all.

There is no way to get into it.

The ghost king's empty phase back then was also because during the Dan period, by chance, he got a mustard stone with a large volume. After refining, you can mobilize a trace of spatial power, and then you can enter it. And as far as the Nian Ghost Monk knew, in order to enter it, the Ghost King Zhukong Xiang extracted too much spatial power, which made the mustard stone that he originally refined not too small shatter and annihilated.

And what was stored in it, the cultivation materials originally collected by the Ghost King's Void Phases were also shattered and annihilated.

However, this decision of the Ghost King Zhukong Phase is obviously correct. Although he has gained something, the Ghost King Zhukong has never explained it in detail. However, not long after the Ghost King Void Phase left this space, he advanced to the Yuan Infant Stage. And this space has also been refined by the Ghost King's emptiness. It has become his own space.

When it comes to retreat, he doesn't stay outside, but returns to his own space.

And in this exclusive space, only a few ghost creatures in the Ghost King's Void Stage can enter it. But he couldn't stay in it for long. Usually, the ghost king gathers all the ghosts to discuss, either in the ghost city of Fengdu, or in other caves in this reckless jungle. This space is hard to get into.

The ghost monk of Wunian once entered this space once, saying that in this space, it was dark and gray. There is earth below, but there is no blue sky above. There are countless spiritual materials that are quite useful for Yin Ghosts, growing in that dark land.

The dark earth is exceedingly vast. A cursory sense of it seems to be boundless. When the Mindless Ghost Monk entered this space, he only saw a corner of this space. I haven't seen a full leopard. However, according to the calculations of the non-mindless ghost monks. The vastness of this piece of heaven and earth is at least the land of a province in China.

This dark world is not suitable for living beings. But it is suitable for the survival of yin spirits and ghosts. In this piece of heaven and earth, the Wunian Ghost Monk also saw a magnificent city, and also saw a lot of powerful Yin Spirit Ghost Creatures. And the name of that city is also called Fengdu!

And the two ghost monks of Wunian and Wuxiang, in this heaven and earth, where the yin aura is more than ten times richer than the ghost city of Fengdu in the outside world, the ghost king Zhukong personally protected the Dharma with the help of the formation treasures, broke through the bottleneck of the Dan period and stepped into the Yuan Infant Period. Therefore, no other ghost thing in the outside world knows that these two of them have already cultivated like this. And Wunian and Wuxiang are therefore extremely loyal to the Ghost King's emptiness.

This ghost city of Fengdu was not built by the ghost kings and the voids, but by the ghosts and immortals in the ancient god transformation period. It has not been washed by the sun, the moon and the earth. Nor has he suffered from the turmoil and turmoil after the Heavenly Immortal Buddha left the earth and went to the universe. It is extremely well preserved.

The Ghost King Zhukong Xiang was able to give up the ghost city of Fengdu and go into retreat to practice, of course, because there was such a powerful existence as the Yin Demon Great Array and the Flower Demon on the other side outside the ghost city of Fengdu. If it weren't for encountering such a strange thing as Yunlei, it would be difficult to break through. And the ghost city of Fengdu is even more strong, and the soldiers are sufficient. If it weren't for the two factions of Shushan and Kunlun to come together to fight, only the Yin soldiers and ghost generals in the ghost city of Fengdu would be enough to wipe out any major cultivation faction in this world. Definitely not to lose.

Moreover, because of the foundation of the ghost king's emptiness itself, only half of it is in this ghost city in Fengdu. The other half is in his space. Even if the ghost city of Fengdu is completely overturned, there is not a single tile left. The Ghost King Void Phases can also rely on the resources in this space to continue cultivating.

will also become the king of the yin spirits and ghosts in this space, who speaks one thing and follows the law.

According to the Wunian Ghost Monk, after Rao Ya was captured, this ghost king Zhukong Xiang did not let the ghosts in the ghost city of Fengdu take over, but brought it into that space by himself.

Yun Lei was originally suspicious, feeling that this ancient famous ghost city of Fengdu was too weak. It is not at all in line with the name of the ancient times. Even if this Fengdu ghost has a sea of flowers on the other side, a great array of yin evil, a city wall full of runes, and a hundred thousand yin soldiers and ghost generals, no matter how you look at these things, you can feel that although they are not small, they are too scattered.

If the ancient era of immortals and Buddhas was full of immortals, the ghost city of Fengdu was just like this, it was really disappointing.

Now that the ghost monk said this, Yun Lei suddenly realized in his heart. It turned out that this ghost scheming actually divided the ghost city of Fengdu into two real and false. Really, the cunning rabbit has three holes.

Cloud and thunder follow this underground cave between the stone stalactites, winding and rugged, uneven roads. Walk towards the depths of this cave. Today, the largest underground cave in the world of mankind has been discovered, and it is the Mammoth Cave of the Appalachian Mountains of the Mayflower Federation on the other side of the ocean. This cave is located in the territory of Kentucky, Mayflower Federation, and it has been detected that the depth of this cave is an astonishing 64 kilometers!

Such a long and wide stretch can already be underground, a world of its own.

In the southwest of China, there are also a large number of similar landforms. Although humans did not find out. However, the huge karst cave that Yun Lei entered today, where ghosts and immortals have been in and out since ancient times, does not seem to be smaller than the mammoth cave of the Mayflower Federation!

Yun Lei was between the stone stalactites, sensing the fluctuations of the spatial power around him, and slowly walked forward, the speed was not too fast. After walking like this for about two hours, the cave has not yet bottomed out. At this time, Yun Lei had already walked out of a distance of about ten kilometers.

And this huge karst cave should have been transformed a little by the ancient ghosts. There are not many forks in the cave. On the contrary, it is the main body, which is huge and incomparable. It's astounding. Walking to this position, the strong flashlight in Yun Lei's hand could no longer shine on the top of the head and the edges of both sides of this cave.

It seems that it should be at least two or three kilometers away, or even longer!

Such a place can no longer be simply regarded as an underground cave sample that can be used to investigate geological and geomorphological changes. Such an underground cave, if built, can simply accommodate a city!

At this moment, Yun Lei's heart moved. A trace of the fluctuation of the power of space faintly swept through the widest part of this cave, and the clouds and thunder were overjoyed.