For seven days, a True Monarch and nearly ten real people have been patrolling in front of C398 non-stop, without giving the barbarians any chance to sneak attack.

Behind them, nearly 10,000 monks were in full swing, and the entire fortress was almost turned over.

Seven days later, a monstrous building took shape.

Inside, it is still built on the mountain, and the area is not much larger, but the appearance of the entire fortress has completely changed.

The Qitian Mountains are close to the left, the veins are abundant, and those low-grade refined iron ore, black iron ore and the like, are even more varied and have great reserves.

Xiang Yang spent three days, running around with Xiaoshan Ju, and almost dug up all the veins within a radius of thousands of miles, fortunately, there was a Qiankun Ding clone, and it was convenient to take it away directly after refining on the spot.

When he returned to the C398 fortress, the Qiankun Ding clone was already stuffed with all kinds of fine iron, and the reconstruction of the fortress had been preliminarily completed.

It took another four days to set it up, and it finally took shape.

According to Xiang Yang's plan, the fortress would be divided into three parts.

The first thing to do is to dig a deep foundation in front of the fortress, and then fill it directly with molten iron to prevent the barbarians from driving the earth-based beasts to sneak attack.

Then, after this foundation, there is the formation area, where he will set up a combined formation composed of nearly a hundred wind array disks, these array disks are not very powerful, and they are easy to manufacture and replace.

The most important thing is that as long as there are ordinary Yuan Qi Stones, even if there are no Yuan Qi Stones, a monk in the foundation building period can use his own Yuan Qi to last for half an hour.

With these formations, when the barbarians use throwing attacks, they can not only slow down the attack speed, but also slightly change the range and angle of the attack, creating dodge conditions for the rear fortress.

And on top of these formations, it will still be covered with a thick layer of fine iron, leaving only an inch of tuyere, anyway, the wind ability, as long as there is a small space, can be played, and even after space compression, the power will be greater.

After these formations, there is the first line of defense of the fortress, according to Xiang Yang's design, this side will present an inverted structure with an angle of thirty degrees, and there are thick metal hooks on it.

This is to prevent the barbarians from self-detonation attacks, will use the best and strongest materials, Xiang Yang found a black crystal vein, use it as the main material, and after the completion of the project, also poured a layer of alloy iron armor on it, according to estimates, with such hardness, the barbarian emperor under the three mountains, after the self-explosion, at most exploded a few zhang square corner.

Later, above the fortress, there is the monk's array platform, which he divided into several areas very intimately, from the three-talent array to the five-element array, according to the size of the formation power and the distance of the casting range, there are special array areas for use, and after all these array areas are activated, they can also be combined with each other to upgrade.

Next to each deck, there are shelters and rest areas to take refuge into, and there are even dedicated medical and backup areas.

Finally, all areas, including the iron foundation at the front, are connected by alloy tunnels, and in the center of the fortress, there is a huge smelting furnace, which can produce huge quantities of alloy iron juice anytime and anywhere, which is easy to maintain.

The entire fortress was covered with a shell made of iron juice.

If you want to make an analogy, today's C398 is like a beehive, with the inside extending in all directions, and the outside is covered with a thick steel shell.

It's no wonder that when C398 was officially completed, those well-informed masters were all dumbfounded after visiting it, and even Huquan Zhenren could only shake their heads and say nothing.

How much manpower would it take for the barbarians to take such an iron mound? If the entire fortress of the Qitian Mountain Range was built like this, the barbarians probably wouldn't even have the courage to attack, right?

But that's not realistic.

In this place alone, Xiang Yang dug up all the ore veins within a thousand miles, and within this thousand miles, there are dozens of fortresses like this, not counting the two defense lines and city walls behind A and B.

Such a steel fortress should cover millions of miles of Qitian Mountain Range? Not to mention the Northern Shenzhou, the entire mountain and sea realm can't come up with so many resources!

This can only be used as a special case...

After doing this, coupled with a few masters in charge, Xiang Yang finally felt a lot more relieved, and completely devoted his thoughts and energy to another important work.

He wants to find out the formation that lurks in the Monkey Sky Mountains!

He wanted to know what the purpose of those orc descendants from the other world was!

Because, as the great war approaches, the deep uneasiness from the soul has become more and more intense, and it seems that in the next moment, a gate to hell will slowly open!

Then, swallow up the entire mountain and sea realm...

Since stepping into the realm of cultivating immortals, his intuition has never been wrong, but this time, Xiang Yang really hoped that he was wrong...

After asking for a detailed map and information of the entire Qitian Mountain Range from Huquan Zhenren, he locked himself in a secret room again, and after three days and three nights, he walked out with red eyes, still finding nothing.

The entire Qitian Mountain Range is completely naturally formed, and in recorded history, there have been no special changes except for a few natural disasters and brutal battles.

In the past 10,000 years, countless Shenzhou monks have explored this mountain range that spans millions of miles more than once, and in some key places, such as the Sanqing Plain, and even dug thousands of miles, but they have never found any clues.

Under this mountain range, it is really impossible to hide such a huge formation...

In three days, Xiang Yang had grown sparse stubble under his chin, his eyes were red, his face was blue, and the whole person looked a lot decadent.

After getting Tianyan, he had never been so powerless, knowing what might happen, but he couldn't grasp a clue.

No matter how magical Tianyan is, after all, it is just a tool that can give full play to his derivation ability, and without the support of sufficient information, it is already an extremely remarkable achievement to be able to calculate the most likely facts through the method of elimination.

However, most likely, it also means that there is still a possibility of error, is this judgment wrong?

So what is the truth?

When Xiang Yang was thinking for a long time, but he couldn't enter the door for a long time, several gorgeous magic boats were galloping away in the direction of Sanqingyuan.

In front of the boat, a multicolored emblem came to life, exactly like the one on the ripples.

On a magic boat at the front, there was a smile on the corner of Lu Ya'er's mouth, and she was looking forward to it.

And beside her, there were not two Dharma Protector True Emperors standing, but a young man, with long silver-white hair casually draped over his shoulders, and his temperament was extremely cold.