The blue-black metal city wall has a height of one hundred and sixty-six zhang, the thickness of the bottom layer is thirty zhang, and the thickness of the top is sixteen zhang, but this height and thickness make Xiao Cheng faint, compared with this great building, in the past and present life, whether it is reality or the fortifications seen in the movie, they have become children in front of the giants, and they cannot be compared at all.

Dense human soldiers with weapons in their hands, patrolling and defending in the corridors opened up above the city walls and in the city walls, the corridors extend in all directions, like spider webs, running through every corner of the metal city wall, as long as you think about the overall length of this great building is 50 million miles, Xiao Cheng feels that he has seen the most incredible dream scene, and he can only admire the infinite creative power of ordinary people in this world.

At the top of the city wall and on the wall facing the enemy country, there are arrow towers of various forms.

Triangles, squares, and diamonds... , There are soldiers stationed in turn, as long as they are on duty, they are fully armed and on alert, once the demons and demons attack the city wall and climb up, these arrow towers are the first line of defense.

It is said to be an arrow tower, but in fact, there are countless weapons to defend the city. Stones blessed by the occult law, flaming wood, and all kinds of venom that poisoned the demon that did not pay for his life...... , of course, the most are the bows and arrows that have been blessed by the occult law.

The arrow tower on the top side is relatively huge, and the huge crossbows that defend the city are arranged, and there are crossbows and arrows several zhang long on them, all of which are in a half-winded state, and as soon as there is a war, they can fight immediately, and the crossbows and arrows that shoot out condescendingly carry the power enough to penetrate the bodies of ten masters of the Holy Realm, as for the demon army, when encountering such a sharp weapon, they can only be ploughed out of a bloody road.

Activating weapons, you need skills and abilities, the warriors on the side of the giant crossbow defending the city are all cultivated to a very high level, the captain is above the holy realm, and the ordinary giant crossbow operator must also be above the six heavenly gates, so that at this height, shoot the crossbow and arrow with the best penetration of the target.

Nangong Ding proudly pointed down at the building and said to Xiao Cheng: "Master Xiao, you see, this is the world-famous metal city wall, and we humans have another name for it, called 'Guardian'." It's a term of endearment, which shows how important it is to the four continents."

Xiao Cheng lowered his head, his eyes penetrated the clouds, overlooking the magnificent guardian, he felt dizzy, and when he heard the words, he said softly: "This is a miracle, I don't know how many people's blood is cast."

Nangong Ding sighed. "Yes, hundreds of millions of people died in the construction process in order to repair the fortifications. But instead of being forced to build the fortifications, they volunteered to participate. The general mobilization of the whole people, each family sent an adult strong man to build fortifications, there were no adult men, the empire was exempted, but there were still strong women carrying tools and rushing to this place to participate in the work in an emergency mobilization of flying magic weapons. The number of people who died of exhaustion in the middle cannot be counted, and the four continents will not... Forget about them".

Speaking of this, the prince choked up, thinking about it, that unbearable past touched his heart. This prince has a heart of worrying about the country and the people, which makes Xiao Cheng have a good impression.

"Your Highness, don't be sad, the guardian has been built, so that the people of today can live and work in peace and contentment, and everything must be paid. ... The demon clan and the demon clan have suffered a lot here, right? Xiao Cheng comforted Nangong Ding.

"It's nature". Hearing this, Nangong Ding adjusted his feelings and said impassionedly: "The guardian who was exchanged for a painful price naturally has the ability to make the two domains of demons tremble. ... Master Xiao, you see, if you look at the guardians from the two demon domains, you will feel that the metal walls they face are all protruding beehives of different styles, and these honeycomb arrow towers that look very terrible are the first steel defense line guarding the human territory.

If the demon soldiers climb up and capture the arrow tower, the arrow tower will immediately break away from the metal wall and fall down, and the soldiers and demon soldiers will die together, and the road behind the arrow tower will be automatically closed, and the guards will protect the car, although it is cruel, but it is extremely effective, otherwise, the demon soldiers will enter the inside of the metal Great Wall from the road, and in that case, it will not be good."

He continued: "The entire city wall is arranged with an unknown number of magic circles, forming a powerful guardian force, the material of the guardian is indestructible, plus the protection of the magic circle, the master of the Holy Realm should not want to destroy the city wall. The guardian attracted the invincible sword qi contained in the Immortal Sword Mountain, and it was arranged vertically upwards along the city wall, forming a huge net of sword qi, invisible, but the master of the Holy Realm could sense it.

This thing blocks the use of flying magic weapons, don't want to transport troops over, the sword qi giant net has a gap, just like a fishing net, with a small grid, this small grid flies sideways alone, and can pass through the sword qi giant net without alarming it, but no matter how small the troop transport flying magic weapon is, it can't be smaller than the huge net space with a diameter of less than two feet, right?

The demon clan's power flew upwards very high, but he was shocked to find that the invisible sword qi giant net was the same as the fairy sword mountain, and he couldn't perceive where the highest place was, and it seemed to extend into the alien dimension, that is to say, it was impossible to leap over this piece of barrier by ascending, so that using the invincible sword qi contained in the fairy sword mountain to build a successful guardian has become the biggest obstacle that the demon and demon clans cannot overcome."

Speaking of this, a gloating smile appeared on Nangong Ding's face, and he said playfully: "The top masters of the two demon clans are extremely angry because of this, and they join forces to attack Immortal Sword Mountain, thinking that if they smash the mountain, the invisible sword qi giant net will dissipate, and they can use flying magic weapons to transport the warriors over and continue the invasion."

But to their shock, the hundreds of masters of the demon and demon clans who joined forces to attack Xianjian Mountain were killed by the peerless sword qi released by the enraged Xianjian Mountain, and a small half escaped with their lives, but the gods and souls were seriously injured and had to retreat to heal. Since then, who dares to attack Xianjian Mountain, isn't that a long life? The two demon domains can only find a way to attack the metal city wall."

Xiao Cheng was relieved, and when he heard that Xianjian Mountain had killed the great masters of the demon and demon clans, a smile appeared on his face, and he motioned for the fifth prince to continue.

"The demons of the Holy Realm formed a commando team, flew to the sky and competed with the Human Sacred Realm for the top defensive point of the city wall, I don't know how many battles have been fought, even if the Holy Realm of the two races of demons temporarily captured the highest point of the city wall, but the masters of the Holy Realm of the Four Continents will be able to beat them back immediately. In the tug-of-war, the demon and demon clans fully realized that it was impossible to break through this dangerous city wall, and only by finding a way to break through the fortress from within.

Over the years, the main battle has focused on espionage and counter-espionage operations, and the demon clan hopes that the traitors in the human race can assist them in destroying the defensive power of the metal city wall.

Nangong Ding said heavily. Obviously, the form is not optimistic. The heart of the demon and the two domains of aggression is not extinguished, so that human beings are like mangs on their backs, and ordinary people do not feel the pressure, as royalty, looking at the scenery, in fact, the pressure is shouldered.

Xiao Cheng looked at the prince whose expression had become solemn, and thought of the saying that women and children on the earth knew - the greater the ability, the greater the responsibility. There is a lot of truth to that.

Nangong Ding talked about his interest, and then said to Xiao Cheng: "In terms of the combat power of the top masters, the four continents and the two domains are basically equal, but in terms of the combat power of the army, they are not afraid of death when they obey orders, and they have not evolved completely, and they only know that the demon warriors of the two clans who obey orders are extremely terrifying. They, one to ten at the same level, are extremely terrifying, and human beings are not a piece of steel, once the guardians are lost, the countries of the four continents are easily eaten one by one.

Fortunately, over the years, the Demon and Demon Domains have tried countless methods, but they have never succeeded, and the guardians have firmly guarded the safety of the four continents, and the people can live and work in peace and contentment, which is completely at work here."

Speaking of this, Nangong Ding didn't say much, and wondered in his heart, how could he say so many words to Xiao Cheng? Perhaps, Xiao Cheng is a very literate listener, right? Nangong Ding found a reasonable explanation.

"Your Highness, according to your introduction, I have a basic understanding of the history and main situation here, there is one thing I want to ask, if there are enough masters of the Demon Clan Demon Clan's Holy Realm, lay down the top-level defensive position, and cover the demon army to climb over, the four continents will be over, right?"

Nangong Ding glanced at Xiao Cheng and suddenly smiled. "You can rest assured that the biggest weakness of the demon and demon races is their numbers, after all, they are more troublesome in terms of fertility, and the number of top masters has never been able to catch up with humans. What's more, in terms of refining, the human race fell to them eight streets, and their combat power was terrifying, but we were outnumbered, and when the masters of the Holy Realm were fighting, the demons and demons didn't want to take advantage of it.

If you want to cover the army to climb over, you need to be stationed at the highest place for at least ten days, and they can't hold it during this time, and the human race will mobilize a qiē force to beat them back. In this regard, we are still very confident." Nangong Ding is full of confidence.

Xiao Cheng smiled. "I'm just a little worried, too, there aren't enough masters in the transformation period above the Demon Two Domains Saint Realm, and most of their city residents are still ordinary humans who have fallen into the Two Domains, I'm a little worried, there will be no such thing as the number of Demon Saint Realm masters surpassing humans."

"Hahaha, of course you're overthinking. It's a strange word, but I understand what you mean. ... In fact, if they had enough Saint Realm masters, they wouldn't need an army, and the Saint Realm masters would penetrate through the gaps in the giant net and kill the top strength of the human race, in that case, the four continents would inevitably be lost.

They didn't do this, because there were not enough of them, and if they wore the whole thing, they would be surrounded and suppressed by humans, and they would still have to flee back, so this aspect was not a problem. In a word, if they want to invade, they need to cross the Guardians, but, can we let it? hahaha". Nangong Ding laughed.

Xiao Cheng was relieved a lot, and smiled, knowing that this person was very good to him, these details, although they are not extremely secret, and they are not known to everyone, this person can introduce them in detail, it seems that he is a friend. Xiao Cheng was a little moved.

At this moment, a giant eagle flying boat cruising at a high altitude approached, and Xiao Cheng was attracted and looked over urgently