Yu Feng said: "Not necessarily, although there was Gu poison at the end of the Great Chaos Period. However, the usable area is very small, and there are not many people who can use it. It has only been on the rise in the last three years. Moreover, the 'Gu Master' has only risen in recent years. Therefore, there are not many high-level Gu masters.

"Gu Master" turned out to be just an auxiliary profession in the martial arts cultivation world, and it didn't attract much attention.

But after the end of the era of chaos, it suddenly became popular. It has become an indispensable role in the martial arts cultivation world, and it plays an increasingly important position among those who have lost the Dao.

The current Gu masters have become more and more a special existence in the martial arts cultivation world, they are equivalent to doctors in the Pingtong world, but they are doctors who understand "martial cultivation".

Moreover, the truly powerful "Gu Master" is far superior to the doctors of the ordinary world in terms of medical skills, because they can use the magical medical department martial arts skills, and the situation they face on the battlefield is also much more complicated!

However, the significance of Gu masters is far from the point of "saving lives and helping the wounded", their functions are much more complicated. They can not only save lives, but also study poisons to kill people invisibly.

What fundamentally changed the status of Gu masters was that they were able to use Gu worms to develop some pills, which could assist the Dao bearers to increase their cultivation speed, an ability they had just developed after the end of the chaos period.

And the rise of the Gu Master is also because of a person, his name is "Canghai Yin", he is a paranoid, and he has devoted his life to the study of Gu worms and Gu arts.

At the end of the Great Chaos Era, he finally developed a new Gu worm called "Yu Qiang".

This kind of Gu worm can be combined with a person's war spirit, and it can stimulate the energy of the war spirit to multiply in a short period of time when the negative Daoist is in a state of cultivation, so that the space of the spiritual hell can be greatly expanded, so that the cultivation speed of the negative Daoist can increase by leaps and bounds.

And the most terrifying thing is that the Gu worm "Yu Qiang" can mutate and turn into a Gu worm with various unknown attributes.

This has also become the ancestor of all Gu worms today, although it is just a short period of more than ten years, but the speed of development is beyond people's imagination!

This established Canghaiyin's status as the "Gu King", and he himself was the first person to receive the favor of this Gu worm. Using this Gu worm, his own level has increased by leaps and bounds, and he is the first batch of people who have successfully ascended to the position by using Gu worms!

However, it was later rumored that he was wanted for developing forbidden Gu worms and forbidden pills, and later it was rumored that he was devoured by malignant Gu worms and his whole body rotted to death.

However, things like Gu worms can't be seen by ordinary people at all, even those who are negative Dao outside the Gu Master can't see them, only Gu Masters can see them. So there are even those who doubt the authenticity of their existence.

However, countless facts have proved that they do exist, and they run through all the Gu Master's medical or drug-making activities.

Gu worms live in the blood of Gu masters, feeding on their war spirits and drinking their plasma. After they die, the Gu worms will also die, but as long as they don't die, the Gu worms will not die.

Other negative Dao people, if they want to become Gu masters, must change their physique through special methods, so that their blood can be suitable for Gu worms to survive.

Gu masters can develop special medicines to improve a cultivator's physique and increase their cultivation speed. What's more, drugs developed through some S-grade raw materials can even be directly upgraded to a higher grade.

According to the speculation of the abilities of these Gu masters now, a high-level Gu master is very terrifying, especially Gu masters who know how to use poison, they are called the real "plague god messengers".

In the event of war, they can cause an army or a city to disappear without noticing.

Therefore, as soon as the poison-making technique of Gu poison appeared, it was listed as one of the "Top Ten Forbidden Techniques" by the whole world.

Thankfully, Gu Masters started late, so it was still rare for Gu Masters to reach this level.

Therefore, there are many people who want to become Gu masters, but this kind of chance is very slim.

When Yu Feng made a comeback, the world of luminescence suddenly changed, and he became a little unable to keep up with the pace, and the growth rate of the current negative Dao was far greater than that of the Great Chaos Era.

The war is over, and more and more masters are emerging, which is an extremely dangerous signal.

And Yu Feng looked at himself, he was still restricted by the "six-pointed star seal", this entry and exit is really double the difference, when will this six-pointed star seal be completely removed......

"This primary method of poisoning is all based on diet, did you eat anything this morning?" Feather Wind continued.

"How do you know so much about this?" said Natsukiri, a little surprised.

"Huh?" Feather Wind knew that he had said a little too much, so he scratched his head and said, "Huh...... I've only seen it from some books, and I don't know if it's true or not, so let's talk about your situation. ”

"I didn't eat this morning, I just drank a cup of strong coffee, but I boiled the water and made the coffee myself," he recalls. ”

"Did you have direct contact with anyone?"

Xia Muli said: "Several people have come to deliver documents, but there is no direct contact. He thought for a moment, and then suddenly said, "The dean of academic affairs sent me a packet of tobacco imported from the tropics, and I smoked a small pot." ”

"Bring me the tobacco leaves. ”

Natsuki took out the tobacco leaves from the drawer and handed them to Yufeng.

Yu Feng took it in his hand and looked at it, and said: "That's right, the problem is in this pack of tobacco leaves, the Gu poison is hidden in it, as soon as you smoke, the Gu poison will run into your body." ”

Xia Muli and Xia Lixue both stared at the pack of tobacco leaves blankly, thinking: How did he see it, and he could tell at a glance that there was Gu poison in it?

Moreover, he knows too much, what is the origin of Gu poison, what kind of killer in the Great Chaos Period, even he can see the level of the other party's poison, it's really incredible, who is this guy?

Xia Lixue looked at Yu Feng's eyes a little stunned, she originally only thought that he was just a little tiger and Gou Youcai, just a gentleman with bad conduct, but now it seems that he is not simple, very not simple!

"How can you tell the Gu poison at a glance?" Xia Lixue asked curiously.

"I've seen simple research, but not proficient. This is a relatively ordinary Gu poison, so I can recognize it. If it's a little more complicated, I can't do anything about it. Yu Feng said, and then asked Xia Muri, "Do you have a conflict with the Dean of Academic Affairs?" Yu Feng asked.

"If there is a contradiction, it is that he had strong opposition when he chose Xiaoxue as the vice principal, but then he agreed, and until now, he has performed well. Namuri recalled.