Lin Tianhan held Su Wushuang's hand and pulled her out of the secret room with the dean and the others.

As soon as he walked out of the secret room, a noisy sound suddenly came into Lin Tianhan's ears.

As I looked at the voice, I saw that outside the secret room, there was a building area.

At this time, this construction area has become a very chaotic battlefield.

Countless skeletons, zombies, and other undead were fighting against a group of cultivators dressed in different armor.

It's just that the whole battlefield, although it looks very chaotic, is showing a one-sided trend.

The human cultivators, according to their different armor, formed four different formations, and were easily strangling the undead creatures that broke into their residential area.

The reason why they can strangle the army of the undead so easily is because they have formed a powerful formation.

The second is that most of those undead are low-level undead, and they are not qualified to compete head-on with those cultivators.

In other words, they are all cannon fodder.

Those low-level undead just broke in and let them kill, draining the cultivator's energy.

In other words, the role of those undead is just to make some trouble for cultivators who are in a resting state.

Although among those undead, there are many spirit-level and true spirit-level undead, but they only know how to rush forward one by one, and they don't consider the cooperation between their companions at all, according to their way of fighting, they will be strangled sooner or later, and become a piece of loess under the feet of cultivators.

Seeing those undead, they rushed forward one after another, and were ruthlessly strangled by the army of cultivators.

Lin Tianhan turned his head to look at Su Wushuang, but found that Su Wushuang looked at his surroundings as if he hadn't seen those slaughtered undead.

Seeing that Su Wushuang didn't react, Lin Tianhan turned his head to look at the four holy spirits behind him.

The four holy spirits, although they are super masters, are also undead.

I don't know how the four holy spirits will react when they see so many undead being strangled by cultivators in waves.

When Lin Tianhan looked at the four holy spirits, he saw that the four of them were just looking at the battlefield for a long time, as if the one-sided strangulation was quite interesting.

Lin Tianhan patted his head, how could this group of people be like this!

As a top master among the undead, he didn't have a normal reaction at all when he saw his kind being ruthlessly slaughtered by cultivators.

Lin Tianhan turned his head helplessly, and no longer thought about things that had nothing to do with him, it was purely self-inflicted.

Looking up, Lin Tianhan found that the place he was in was still a relatively high place.

Lin Tianhan stood on tiptoe and scanned the surroundings, hoping to see farther away.

Sure enough, standing on tiptoe, I looked farther.

Under Lin Tianhan's glance, the general appearance of the entire underground world was under Lin Tianhan's eyes.

In the middle of this underworld is a large mountain with four peaks.

On the body of the mountain, there was a dull shroud.

The dim light shield enveloped the entire mountain, and it seemed that even the mountain located underground was enveloped by the dim light mask.

On the mountain inside the dim light mask, from time to time, there were one or two unclear attacks, hitting the light mask, and the light mask was flooded with ripples.

And outside the dim light mask, there were actually a large number of undead creatures, constantly attacking the dim energy light mask.

What shocked Lin Tianhan was that those undead who attacked the dim energy shield were actually all quite strong.

Among them, the weakest ones are all spirit level, and the undead at the true spirit level are even more grasped.

It's just that what makes Lin Tianhan strange is that according to the strength of those undead, they kept attacking the dim energy mask, but the dim energy mask didn't even react at all, and not a single ripple appeared.

Then it can be deduced from this that the guy who shoots in the energy mask from time to time, how powerful they are.

But Lin Tianhan also had a doubt, that is, so many high-level undead, knowing that it was useless to attack that seal, why would they still be so happy and keep doing useless work?

In fact, when Lin Tianhan saw the ring-shaped city wall that surrounded the entire mountain, he understood the reason.

It's not how tall the circular walls are to hold back the undead from attacking.

Not at all, this circular wall of the underworld is much shorter than the wall of the Sky City on the ground.

Why is it that such a short city wall can still block the attacks of countless high-level undead?

The reason is that on that city wall, there are powerful crossbows of the gods.

The Divine Crossbow is not only extremely powerful, but also has a very good range and accuracy.

Just now, Lin Tianhan also saw a soldier wearing red armor pulling out the Zhushen crossbow and shooting an arrow.

That arrow flew out in an instant, and before Lin Tianhan could see it clearly, the arrow had already hit the head of an undead who was desperately attacking and was covered with dim energy.

The true spirit-level late-stage undead who kept attacking the energy light shield was actually directly shot in the head by that arrow, and fell instantly.

Feeling the strength of the divine crossbow, Lin Tianhan couldn't help but 'grunt' and swallowed his saliva.

Wow Ka Ka!

This god-destroying crossbow is really as strong as the legend!

Seeing the strength of the Zhushen crossbow, Lin Tianhan thought that the Mixed Yuan Continent was about to be unsealed, should the God and Demon Hall be equipped with a large number of Zhushen crossbows?

In this way, when facing the impact of armies from all walks of life, there can also be some explosive killing methods.

Just when Lin Tianhan was thinking about how to get the Zhushen crossbow to make drawings.

The Dean of the Sky Academy, who was the master of this place, looked at the four guardians who had never intended to speak, sighed helplessly, and then said to Lin Tianhan and Su Wushuang, "This is the underground world. ”

"There are 40,000 elite soldiers stationed here all year round, guarding the seals of the four holy spirits. ”

The seal has a powerful magic (human) seal, a geographical seal, and a heavenly time seal.

The so-called magic seal is actually the power of the enchantment seal laid by countless top cultivators.

The so-called geographical seal is the earth seal arranged according to the geographical location of this place.

The Last Heavenly Time Seal, although it seems more complicated, is the most simple and crude.

The so-called Heavenly Time Seal is to take advantage of the suspension of the Sky City to directly fix the Sky City in the air of the sealed place, and guide the powerful gravity of the Sky City directly into the ground, binding the two sealing arrays below more firmly.

The Dean of the Sky Academy pointed to the undead in the distance and said, "Because the core divine stone of the Sky City was stolen, the Sky City lost control and lost its ability to suspend in the air, so the Sky City fell down and pressed on top of the Mercenary City. ”

Lin Tianhan asked curiously, "Lord Dean, who stole the core divine stone of Sky City, do you have any eyebrows?"

"Of course, intelligence has always been a top priority in the development of Sky City. ”

The Dean of the Sky Academy said this, but he sighed helplessly.

"Hey, it's just that although we found out who stole the Core Divine Stone, we don't have the ability to recover the Core Divine Stone. ”

"Why?" Lin Tianhan asked suspiciously, "Is there any unavoidable reason?"

Lin Tianhan was really shocked, with the strength of Sky City and Mercenary City, he actually said that he had no ability to recover the lost core divine stone, how could this be possible?

Not to mention those hidden hermit masters in the Sky Academy, even those young masters in the cultivation world who are a large number of masters, and they are not dry food.

Those many academy students, as long as they are mobilized, let alone a few treasure thieves, even a spirit king-level master, can also pile him to death.

But why did the Dean of the Sky Academy say that he didn't have the ability to chase back the Core Divine Stone?

Just when Lin Tianhan was puzzled, the Dean of the Sky Academy slowly opened his mouth to explain.

It turned out that after the core divine stone was stolen, the sky city fell.

Fortunately, when the ancestors established the mercenary city, they considered this matter, so now there are no incalculable serious consequences.

Although the Mercenary City was safe and sound, with the theft of the core divine stone of the Sky City, the two sealing formations underground suddenly became fragile.

The four holy spirits who had been preparing for tens of thousands of years and had been waiting for the day to see the light of day again, after feeling the fragility of the seal, the four holy spirits who didn't think about it seemed to have telepathy, and attacked the same place at almost the same time.

In the face of the simple and decisive judgment of the four holy spirits, the two powerful seals were suddenly blasted out of a gap by the four holy spirits.

Fortunately, the guardians who guarded this place were super masters, and when the seal moved, they reacted in time.

Only after the double seal was blasted out of the gap, he was fully prepared.

In the face of many masters of the Guardian lineage, relying on the power of seals, they kept suppressing the four holy spirits.

While suppressing the four holy spirits, repair the sealing array.

With all the masters in the two major cities of Sky City and Mercenary City, successively devoting themselves to suppression and sealing, the four holy spirits were re-sealed.

It's just that although the four holy spirits have been resealed, the sealing gap that was blasted out by the four holy spirits will not be repaired for a while.

Because when they were repairing, the four holy spirits could summon countless low-level undead through the sealing gap and harass them with the power to repair the seal.

Therefore, repairing the sealing array not only consumed a lot of manpower and material resources, but also consumed time.

To this day, the broken seal has not been repaired.

Originally, even if this underground world consumes so much manpower, it is still very simple to hunt down a few thieves.

As long as you publish a public mission in the mercenary union, this matter can be solved perfectly.

But I don't know if it's unfortunate, or if the other party has premeditated.

Just when everyone in Sky City was about to launch a large number of mercenaries to recover the core divine stone of Sky City, bad news came from outside Sky City.

It was just a night's effort, and the sky city sitting on one side was actually surrounded by countless armies of undead.

Although the core divine stone is very important, the city in the sky and the city of mercenaries are even more important, so they can only give up recovering the core divine stone and defend against the attack of the undead army with all their might.

After listening to the dean of the Sky Academy, Lin Tianhan couldn't help but sigh.

Who would have thought that the city in the sky, which dominates one side, would actually have such a dilemma as it is now.

I lost the core divine stone, and I couldn't do anything to recover it, which is really a shame for the boss.