In addition to being used for circulation, one of the biggest uses of blood crystals is that they can be fed to the dragon and absorbed by the dragon.

Generally speaking, when a dragon evolves to the prime of life, it will not continue to evolve, and as time increases, it will slowly enter old age. However, if you give the dragon Blood Crystal during the prime of life, the dragon's constitution will gradually change. The first dragons, such as Xue Yi's current dragons, are all called sub-wurm, and after the physique changes, the dragon will become a wurm.

And dragon knights are also divided into sub-dragon knights and wurm knights according to different dragon species. Compared with the Wulong Knight, the sub-dragon knight is inferior in terms of status and strength.

In terms of Xue Yi's current dragons, they are all sub-wurms, and Xue Yi is just the most ordinary sub-wurm knight on this continent.

Sub-dragon knight to dragon knight, it is very difficult. The dragon needs to absorb at least hundreds of blood crystals to reach it, but blood crystals are extremely rare, so in the entire killing continent, the number of sub-dragon knights is very large, and the number of sub-dragon knights is less than one percent of that of sub-dragon knights.

Of course, above the Wurm Knight, there is also the legendary Bloodline Dragon Knight, which is a stronger dragon knight than the Yalong Knight. It's just that no one knows how to achieve the Bloodline Dragon Knight, or its method has been lost. Therefore, the Wulong Knight became the highest-level Dragon Knight on this continent.

Thinking of this, Xue Yi smiled bitterly, he had struggled in the Holy Dragon Continent for so many years, and had become the first person in the Holy Dragon Continent, thinking that after coming to the Killing Continent, he could be regarded as a medium level. Unexpectedly, it was just the worst sub-dragon knight.

But fortunately, with so many blood crystals, it should be enough for all of your dragons to evolve into wurms.

His soul moved. Collecting the blood crystals into his own space, he walked out of this room and opened another door.

I saw that in this room, there were more than twenty tall bookshelves neatly placed, and on the bookshelves, there were some classics that looked like they had been going for a long time, and Xue Yi's soul swept. Two books were quickly locked.

The two books are very close together, with only one book in between.

Xue Yi pulled out the book on the left first. In fact, strictly speaking, this is not called a book. It would be more appropriate to call it a map. At the top, the name of this map is written in Langhua characters: "Map of the Eastern Continent".

Xue Yi's heart moved, and he glanced at it, only to see that there was a text annotation on it: three hundred and twenty continents, divided into four continents: east, south, west, and north. The smallest continent in the Eastern Continent. It is called the Holy Dragon Continent, and the largest is the Haohan Continent.

Xue Yi smiled bitterly, it turned out that the Holy Dragon Continent was really only the smallest continent.

Looking at the map above, I saw that the Holy Dragon Continent was not only the smallest continent in terms of territory, not even one percent compared to the Haohan Continent, but also the most remote continent.

And the Killing Continent is the closest to the Holy Dragon Continent on the map, and its area is equivalent to thirteen Holy Dragon Continents.

These continents are not connected, they are in different spaces. If you want to go to another continent, you must find a barrier similar to the very center of Ryujin Island. Plainly. That kind of screen is actually similar to a teleportation array, but it is much more powerful than a teleportation array.

Finally, there is a sentence under the map: If you want to pass through other continents, you must pass through the Haohan continent.

Xue Yi smiled bitterly again, just the Haohan Continent was separated from the Killing Continent by nearly twenty continents, and every time he went to a continent, he had to find a barrier similar to the center of Dragon God Island. These barriers are generally very little known. It seems that it is really difficult to go to the Haohan Continent.

But soon Xue Yi forcibly erased this trace of thought in his heart, and his eyes showed a resolute look.

For the sake of Lei Yu Sitong, no matter how difficult it is, he must go to the Haohan Continent and the Tianwei Continent to find a way to kill the Tianwei King.

Xue Yi put the map into his space again, and then looked at the other book next to him.

In the meantime, he swept his gaze over the book in the middle, and saw that it read "Exploration of the Underworld".

Xue Yi didn't care about this book, in the Holy Dragon Continent, the Hades Mansion was just a legendary existence. Although people say that all things must return to the underworld after death, according to Xue Yi's understanding, after all creatures die, their souls are dissipated into the air, and they don't go to the underworld at all. So Hades is nothing more than something that people imagine.

Therefore, Xue Yi's gaze skimmed over this book, and landed directly on another book next to him, and quickly pulled it out.

On the cover of this book, there are two words - "Quick Knife".

Xue Yi laughed secretly in his heart, this name is also too cheesy, if the characteristics of this knife are fast, wouldn't it be very fashionable to call it "lightning knife" or "shadowless knife"?

Xue Yi probably turned two pages and knew that this fast knife turned out to be a knife technique that brought the word "fast" to the extreme. All its essence is in one "fast" word, and sometimes even other aspects are compressed as much as possible for the sake of the word "fast", at the expense of reducing power, sustainability, and power...... All of this is for the sake of a "fast" word service. If it is fast to Dacheng, it can even kill tens of millions in an instant.

The "kill 10 million in seconds" here does not mean that you can kill 10 million with a big move, but kill 10 million one by one, but because its speed is too terrifying, it will kill 10 million in a few seconds. One can imagine how terrifying its speed must be.

Xue Yi read a few pages, tried to practice a few times, and found that his speed had really improved a lot. At least the speed of his moves can be two or three seconds faster than before.

Don't underestimate these two or three times, in a duel between masters, a tenth of a second can decide life and death. And these two or three seconds are enough for the opponent to die dozens of times.

Xue Yi closed the book and looked at the word "fast knife" on the cover of the book, and then he knew why it was called such a cheesy name as "fast knife". The essence of the fast knife is the word "fast", and even the name reflects the word "fast" vividly. Just saying the word "fast knife" is always a third faster than "lightning knife" and "shadowless knife" and the like.

Xue Yi was determined to study and study the fast knife in the future. He put the book in the space, and was about to turn to leave the room when his mind suddenly moved.

I saw that the books in the entire room suddenly disappeared, and all of them were collected into the space by Xue Yi, these books were kept, and maybe they would be used in the future.

Then Xue Yi entered the third room.

But the room was empty, there was nothing in it. But on the ground, there is a pattern depicted. The pattern is circular and surrounded by many strange symbols. Xue Yi glanced at it a few times, but he didn't know what this pattern was.

With his cautious character, he naturally does not move around things that he does not understand, especially when he comes to an unfamiliar environment.

So he exited the room, exited the palace, released the evil spirit dragon from the space, and then took out a fire attribute blood crystal.

He tossed the blood crystal in his hand and threw it at the Evil Spirit Dragon.

The evil spirit dragon hadn't come out for a long time, and as soon as it came out at this time, it was immediately refreshed, and was about to roar to express its comfortable emotions. But at this moment, his body suddenly froze, and he turned his head to the place where the blood crystal was thrown. From the blood crystal, it felt an extremely large fire elemental aura.

The evil spirit dragon did not hesitate, and swallowed the blood crystal in one gulp. A moment later, in the body of the evil spirit dragon, the huge fire element began to roll over, and gradually began to transform the body of the evil spirit dragon. However, this kind of transformation is very slow and far from meeting Xue Yi's requirements.

So Xue Yi's soul moved, and a large box with a height of one person appeared in front of him, and he slapped it casually, and the lid of the box flew out. Xue Yi swept his hand, and dozens of blood crystals flew towards the evil spirit dragon. The evil spirit dragon opened its mouth and swallowed all the dozens of blood crystals.

So in the body of the evil spirit dragon, the speed of the transformation was much faster, and it was almost visible to the naked eye.

At this time, Xue Yi swept again and gave more than twenty pieces of blood crystals to the evil spirit dragon.

After the evil spirit dragon swallowed it, his body suddenly changed. The scale armor on its body began to fall off piece by piece, and as the scale armor fell off, it seemed to break free from its restraints, and its body began to grow larger. In just a few moments, the length grew to more than 200 meters, and the wingspan reached more than 150 meters. And on its body, it exuded an extremely large aura of flames.

Its head, although still a skeleton wrapped in flames, can be seen that its skeleton is no longer white, but a fiery red color. This is enough to show that the skeleton dragon has been transformed from the inside out.

This is just an external performance, Xue Yi used his soul to probe, the strength of the evil spirit dragon at this time has reached an extremely terrifying level, even if it is his full strength, at this time, at most, the evil spirit dragon can only be slightly injured, but it cannot hurt the root. Even if the original Slaying Dragon came to fight against the Evil Spirit Dragon, the Evil Spirit Dragon would not be left behind.

At this time, if the evil spirit dragon was put back into the Holy Dragon Continent, it would be able to sweep through the entire Holy Dragon Continent with just one of them, and there would be no need for Xue Yi to make a move.

Such an evil spirit dragon can be called a real wurm species, and Xue Yi also got rid of the low-level sub-wurm knight and became a wurm knight.

If the dragon knights of the Killing Continent knew about this, they would definitely be so surprised that they couldn't keep their mouths shut. They have exhausted their whole lives to become a dragon knight, but few of them can really become a dragon knight, and Xue Yi has only been in the killing continent for a few hours, and he has become a dragon knight, which is also too disturbing.

The evil spirit dragon has evolved from a sub-sub-dragon to a sub-dragon, and at this time it is in a good mood and flies around the palace to its heart's content.

Xue Yi glanced at the box, there were about a hundred blood crystals, and released the magma dragon as well. Throw all 100 Blood Crystals to the Magma Dragon. As Xue Yi expected, after the magma dragon absorbed these hundred blood crystals, its body also grew to more than two hundred meters.

Xue Yi was overjoyed, threw the empty box into the sea, and with a movement of his soul, he took out another box. (To be continued......)