The only thing about Su Xiaofan's personal space that is not as good as a small cave is that the space inside the body cannot be displayed and used for living and resting.

"You can just refine a small cave, but there is no need to integrate it into the body."

Su Xiaofan thought for a while and came up with an idea. He only needed this small cave to be able to carry it with him, and then use it to rest outside.

As for storage, the space inside Su Xiaofan's body is more than a hundred times larger than that of a small cave, so there is no need to put the cart before the horse.

"Huh? To build a cave residence, you need to use spiritual wood?"

Su Xiaofan noticed one of the requirements, which was to use spirit wood to carve formations on it.

Ordinary wood is not good enough. Even the Xumi formation cannot be carved on it. Naturally, the cave cannot be retracted or enlarged.

"This thing seems easy, but it is very troublesome to make."

After Su Xiaofan read the methods and steps for making a small cave dwelling, he couldn't help but shake his head and smile bitterly.

Su Xiaofan's cultivation level is sufficient, and he also has the strength to seal a small space in the turbulent space, so there is no problem with this.

But if the cave structure with the formation engraved on it cannot be combined with the space, naturally this small cave residence will not be able to take shape.

What Su Xiaofan is lacking now is materials. There are some messy alloy materials in the space inside his body, but those things cannot be used in this cave.

"Forget it, pay more attention in the future and collect these materials when you encounter them."

Su Xiaofan shook his head, put away the jade slips used to make the small cave, and then took out the jade slips used to refine the secret door.

Compared to a small cave, that thing is not a necessity, it just makes Su Xiaofan's life in the starry sky more comfortable.

But the secret door is something Su Xiaofan attaches great importance to.

According to what Venerable Huo Tian said, the Great Secret Realm seems not to be in the universe, and the materials and resources produced in it are all needed by cultivators of Immortal Lord, Golden Immortal and above.

Although the cultivation system is different, Su Xiaofan does not need the resources of the cultivator very much, but Su Xiaofan needs the repair value.

Many of the cultivator's materials and resources can be converted into repair values. The more precious they are, the more repair values ​​they can be converted into, so Su Xiaofan is now coveting the great secret realm.

“Damn it, where can I find so many materials?”

When Su Xiaofan saw the materials needed to refine the secret door, he couldn't help but be stunned.

There were actually thousands of materials listed in the jade slip, and Su Xiaofan had never even heard of 99.9% of the materials.

"No, I have to ask Venerable Huo Tian for a book that specifically introduces the treasures and materials of heaven and earth, otherwise I won't recognize it even if I see it."

Su Xiaofan gave a bitter smile and continued reading. He already had the basic materials for refining the secret door, but Su Xiaofan didn't want to refine an ordinary secret door. If he wanted to refine it, he would refine it with the best.

The jade slips given by Venerable Huo Tian were introduced in great detail, and the quantities required for each material were also listed one by one.

Su Xiaofan's expression slowly softened, because he discovered that among the thousand kinds of materials, more than 900 were not needed very much, they were all auxiliary or additive-like things during refining.

There are only three materials that are in greatest demand. Whether it is quantity or quality, the more, the better, the better.

The first is the Yuan Stone. It is introduced in the jade slip that the Yuan Stone is produced in the Yuan Stone veins in the Great Secret Realm.

To refine the secret door, you need middle-grade or above Yuan Stone, which costs at least 3,000 yuan. The more quantity and quality, the better. There is no upper limit.

If the secret door can be refined with top-grade yuan stones, the distance that the secret door can teleport is at least a hundred times that of the secret door refined with medium-grade yuan stones.

Yuan stones are not very rare in the Great Secret Realm, but all cultivators, including powerful cultivators, have a need for Yuan Stones.

The output of Yuanshi veins is not large, and usually the Yuanshi in the great secret realms that have been developed have been mined out long ago.

Yuan Stone is also the currency circulating in the Great Secret Realm. If some cultivators who meet in the Great Secret Realm want to trade with each other, they can use Yuan Stone to settle.

"Venerable Huo Tian is so particular..."

Su Xiaofan took the time to glance at the storage ring given by Lord Huo Tian, ​​and immediately discovered the small pile of primeval stones.

Each piece of Yuan Stone is not big, only about the size of a thumb. It exudes an energy that Su Xiaofan has never seen before, and the small pile is exactly three thousand pieces.

Su Xiaofan knew without thinking that these three thousand Yuan Stones must be middle-grade Yuan Stones, and there was absolutely no way that Venerable Huo Tian would give the high-grade Yuan Stones to him.

In fact, Su Xiaofan didn't know that top-grade and top-grade Yuan Stones were really difficult to obtain, especially top-grade Yuan Stones, which could even be auctioned in some great secret realms, comparable to those treasures of heaven and earth.

The fact that Lord Huo Tian was able to find so many Yuan Stones for Su Xiaofan was already very valuable. If it weren't for the transaction between the two, Su Xiaofan wouldn't even know what the Yuan Stones were.

"There is no limit, grandma. If the secret door is refined with 30,000 pieces of top-grade Yuan Stone, can it be directly transmitted to the original galaxy?"

Su Xiaofan drooled when he saw the introduction in the jade slip. He decided to stop refining the secret door if he didn't get the top quality Yuan Stone.

Because after the secret door is refined, it will become your own natal magic weapon, and it will basically be difficult to improve its quality in the future.

Venerable Huo Tian also asked Su Xiaofan to be more cautious in the jade slips. It would be best to collect some top-quality materials before starting to refine the secret door.

"Yuan Shi, remember!"

Su Xiaofan firmly remembered the fluctuations emanating from the Yuan Stone in the storage ring in his mind.

This way of recording things is the most accurate and convenient. From now on, Su Xiaofan will not need to use his eyes to see, he can detect it as long as his mind touches it.

"Amethyst? What kind of material is this?"

Su Xiaofan saw the name of the second main material, which he had never heard of before, so he continued reading.

"It's not easy to find this thing either."

Amethyst is also produced in the Great Secret Realm, and it has appeared in all realms of the universe, but only a few people have gotten a little bit of it in the nebula, and the number is not very large.

Amethyst is actually not a crystal, but a mineral. It is the essence extracted from purple black iron. Usually, only three or five pieces of amethyst can be extracted from a purple black iron vein.

As for refining the secret door, you need at least a thousand pieces of amethyst, and the more the better, if there is no upper limit.

Compared with Yuan Stone, Amethyst is much rarer in the Great Secret Realm, and it is very difficult to find.

Because the purple black iron ore veins are almost indistinguishable from ordinary black iron ore veins.

There are many black iron ore veins in the Great Secret Realm, and the purple black iron ore veins are hidden among these ordinary black iron ore veins.

Many cultivators have been mining in the Great Secret Realm for many years in order to obtain amethyst, but the chance of being able to dig out the purple light black iron veins is very low.

Of course, this thing is the same as the Yuan Stone. As long as you have perseverance and find a large secret realm with more black iron veins, you can still get a thousand amethysts.

There once was a Golden Immortal Venerable who just wanted to make his secret door of higher quality, so he spent a lot of money to enter a great secret realm through someone else's secret door.

The Golden Immortal Venerable was very perseverant. He actually stayed in the secret realm with many black iron veins for half a million years and refined 3,000 pieces of high-quality amethyst.

Just imagine, it took half a million years of mining to extract three thousand pieces of amethyst. The output of this thing is so rare.

Of course, there are also some lucky Golden Immortal Venerables who accidentally stumbled upon a rich mine of purple black iron when they went to the secret realm for the first time.

The Golden Immortal cultivator only dug for a month and collected all the amethysts needed to refine the secret door. The remaining amethysts were sold at a good price.

"We have to find a way to find a great secret realm to enter, preferably one with rich resources."

After seeing these two things, Su Xiaofan was a little scratched his head. These things are not available in all realms of the universe or are very rare. The only way to get them is to go to the Great Secret Realm.

"Look for an opportunity to ask Venerable Huo Tian if you can enter the Great Secret Realm with him."

Su Xiaofan pondered for a long time, and it seemed that he only knew Venerable Huo Tian, ​​a golden immortal with a secret sect. It seemed that he had to continue to pull out the wool.

Continuing to look down, Su Xiaofan actually knew the third material that was needed in large quantities, and he had obtained it before.

"Void Spirit Stone!"

Su Xiaofan did not expect that the last main material of the secret door would be the ethereal stone.

He had gotten a few pieces of this thing from his disciple He Lianxiong before, and later refined some pieces of storage equipment and gave them to his family, but now he doesn't have any pieces.

But even if there are, those ethereal stones are not suitable for refining the secret door.

According to the introduction of Venerable Huo Tian, ​​the ethereal stone is also called the space spiritual stone, and it can be divided into four grades: upper, middle, lower and top quality.

If you want to refine the secret door, you need at least one hundred high-grade ethereal stones.

What Su Xiaofan got back then was just a low-grade ethereal stone. At best, he could only refine some storage equipment with little space.

High-grade ethereal stones are extremely rare, and they do not exist in the universe. However, compared to the above two main materials, ethereal stones are easier to obtain.

Because the ethereal stone is produced in the turbulent space, it can be entered by the Golden Immortal. Compared with the Immortal Lord, the turbulent space poses less of a threat to the Venerable.

So as long as you work hard and stay in the turbulent space for tens of thousands of years, you can still get a hundred high-grade ethereal stones.

Of course, one hundred high-grade ethereal stones is only the lower limit, and there is no upper limit.

The main function of the ethereal stone is to stabilize the secret door space.

The more ethereal stones used and the higher their quality, the more stable the space of the secret door will be and the farther the teleportation distance will be.

For example, the golden immortal whose secret door collapsed as mentioned before was anxious to refine the secret door and went to the Great Secret Realm because he was missing more than a dozen ethereal stones. He made do with more than 80 ethereal stones and started refining it.

The Golden Immortal was successfully refined and went to the Great Secret Realm, but after using it five or six times, the secret door collapsed when it was opened, and the Golden Immortal is still missing.

Therefore, the quality and quantity of the ethereal stone can be said to be the most important among the three main materials, because this thing is directly related to the life of the cultivator.

In addition, if more ethereal stones are used, more people can be teleported by opening the secret door at one time, which is a huge investment for the Golden Immortal.

You must know that the resources required for Venerable Jinxian to open the secret door through one person and through five people are the same.

If more than five people pass through a secret door at one time, more resources will be opened, and the quality of the secret door must be higher.

As for more than ten people passing through the secret door at one time, it is extremely rare and rare.

Only those very powerful Jinxian cultivators, or Daluo or even powerful cultivators, have such secret doors.
To be continued...