Just a few hundred zhang away, a huge cave appeared, with a width and height of a hundred zhang.

It was dark and I couldn't see how deep it was, and even if I used the Eye of the Starry Sky, I could only vaguely see that there were countless forks in the inside, and I didn't know where it went.

Bursts of thick evil qi and other poisonous gases mixed with the blowing, extremely cold, blowing a strange vortex of different sizes at the entrance of the cave, and the sound of whimpering faintly came, as if a ghost was crying wolf, and the legendary entrance to hell was nothing more than that.

Li Wuding is not afraid, in fact, these evil breaths blow on him, and they are very comfortable!

He took out a box of military mini drones from the storage ring, each drone is only the size of a thumb, this is the so-called "little bee" drone, with the assistance of artificial intelligence, can detect autonomously or in groups.

With a "buzz", three hundred mini-drones plunged headlong into the unfathomable cavern like an abyss, and began to map all the passages.

I don't know how long this process will take, Li Wuding has nothing to do, runs to a hole with the strongest evil qi, opens the spiritual root, and comfortably absorbs the evil qi.

Hey, last night was really too much consumption, this will meet this opportunity to make up for the big thing, how can I let it go.

After waiting for two hours, the drones flew back one after another, and all the data was quickly uploaded to the military laptop, and an underground labyrinth like a spider's web was finally presented in front of Li Wuding.

The image transmitted back by drone No. 133 is extremely weird, there are obvious infrared fluctuations, and the space of the cave is huge, so the cave is simply numbered 133.

Li Wuding hurriedly enlarged the image to check it, although it was not clear, but the infrared image showed that there was indeed a huge round man-made object there, with a diameter of at least 100 meters.

"This is it!" he was a little excited, according to the best path he had calculated, the distance to reach Cave 133 was 60 kilometers, which was actually not far, but there were nearly three thousand forks in the road to pass, and it was really difficult to get out alone when the divine sense could not be used.

A three-dimensional map of the structure and route was entered into Li Wuding's brain, and after confirming the direction, he took out a Gatling and flew into the hole.

As the distance deepened, the light in the cave became more and more dim, and he did not turn on the searchlight rashly, but used the eye of the starry sky to harmonize

Infrared night vision device assists in observation.

On the wall of the cave, a thin layer of black crystals began to appear, shining on them, and it seemed to condense a layer of black ice, and bursts of gloomy and sympathetic breath seeped out from above.

"What is this?" Li Wuding curiously broke off some crystals and rubbed them slightly, these crystals immediately turned into black mist, and it was very comfortable to penetrate into the skin coldly.

It turned out to be a crystal condensed by evil qi, but it was a bit like a evil stone, but it was not as strong as a evil stone.

After entering the distance of ten kilometers, the evil qi, which was much thicker than the entrance of the cave, roared and circled in the cave passage, making bursts of startling screams, which made people's hearts beat and their hearts were unsettled.

The crystals here are also getting bigger and bigger, becoming the size of eggs, densely arranged on the stone walls, and the scalp of people is numb to see.

The reason why there is such a place where the evil qi is so strong here has a lot to do with the geographical location of the Gray Spirit Continent, although the aura still occupies the protagonist here, but the distribution of the evil qi is the most extensive place in the spirit world, and there are quite some characteristics of the demon world, probably because of this, those monks of the demon world will choose to appear here.

When approaching Cave No. 133, a stream of black air with different properties began to appear in the black qi that permeated the surroundings, and Li Wuding felt it a little, and he could determine that this was a bad qi of different attributes. In fact, it is not surprising, just like the multi-minute attribute of spiritual energy, evil qi is also multi-minute attribute, but in the spiritual world, it is extremely difficult to encounter such a rich mixture of evil qi. This gas was highly toxic to the other monks, and it was a great tonic for him.

This was the first time he had come into contact with different attributes of evil qi, and he felt very unique, his body moved while absorbing it, and it was absorbing it in all directions.

If they don't have a very powerful elixir to protect them, it is conceivable that they may not be able to hold out for a few hours inside, and even if they run out, their cultivation will inevitably be greatly damaged, so it is no wonder that they can't run far.

He also felt that these evil qi were not completely naturally gathered, as if there was some magic circle in control, and once someone stepped into this huge magic circle, the corresponding evil qi would gather and act as a barrier.

This discovery made him suddenly alert, if there was really a large magic circle here, then obviously the appearance of those Demon Realm monks was not accidental, it was possible that this was a long-term operating base, so you need to be especially careful.

He carefully followed the direction in which the evil qi flowed

Looking for the formation, after turning a corner in the road ahead, a black protrusion like a tomb suddenly appeared on the side of the passage, and there were high and low black array pillars scattered around it, and a magic circle similar to the Nine Palaces Bagua Spirit Gathering Array was constructed according to the terrain.

This magic circle is really clever, as long as someone passes nearby, the magic circle is activated, and the black wind that gathers from the surrounding area is howling non-stop, and the violent anomaly is far from being comparable to the yin wind in the passage.

"Hey, what is this?" In the darkness, Li Wuding saw a little phosphorus fire, flickering, floating out of a cave not far away.

Li Wuding's figure flickered, and he came to the entrance of the cave in an instant.

After a sweep of his gaze, even if he was as bold as him, his complexion changed slightly.

This is a cave that is wide and high to reach dozens of zhang, the cave wall inside is like crawling with fireflies, flashing with faint green light, in the center of the cave, there is a small altar, there are many stone pillars densely standing on the altar, on each stone pillar, there are several dried corpses tied, some have broken hands and feet, some have only half of their heads, miserable.

The strange thing was that there was a small black tube inserted in the position of the dantian qi sea in the abdomen of all the corpses, and Li Wuding curiously ingested one in the air.

After taking a closer look, he found that this was not an ordinary tube, but a magic weapon, and there was a faint forbidden mana on it, and after a little study, he immediately understood that this was a very poisonous magic weapon.

Previously, when he was copying materials in the library of the Formation Law Academy, he had seen an ancient "Spirit Extraction Technique", and he used this magic weapon called "Blood Spirit".

The principle is to close the sacrificial monk's * meridians, and then insert the "blood spirit" into the monk's dantian qi sea, and the "blood spirit" will extract the monk's mana, and then compress it into the blood plasma and flow out, because these plasma are rich in the monk's mana, can be used for some mysterious evil arts, and can also be used for some cultivation of evil skills.

But that book only describes this evil magic weapon, but does not give a method of making it, nor does it point out what kind of evil magic and evil skills need to use this kind of thing, but I didn't expect to encounter it here.

The most cruel thing about this kind of evil art is that the process of blood sacrifice must be a living sacrifice, in order to make the mana of the blood sacrifice monk better integrate into the blood plasma, so the process of dripping blood is very slow, the book says that it generally takes nine days, and the high-level monks are far more than that!

It's more than nine days! Just watching the vitality slowly pass away, it's terrifying!