Cao Cao watched around the battlefield and immediately became surprised.

Although there are very few people on Liu Yu's side, every soldier is well-equipped, coupled with the support of heavy artillery, even if there are only 5,000 people, I am afraid that Cao Cao will have to pay a considerable price if he eats them.

And more importantly, there is a Dugu Yan behind Liu Yu, if this old fox intervenes halfway when he and Liu Yu are in a fierce battle, then the outcome of this battle will be even more unpredictable.

After returning to the barracks, Cao Cao seemed preoccupied.

"I don't know why I'm bothered by assists?" Guo Jia appeared beside Cao Cao like a nobody.

"Liu Yu will definitely become my confidant in the future, but now I have no means to check and balance him." Cao Cao bit his head and said.

"The army is already under the city, why not take the city in one go?" Guo Jia pretended to be surprised and said.

Cao Cao gave him a blank look, as if he was wondering why Guo Jia couldn't even see this.

"We have worked far away this time, although we have won a battle, but the soldiers are sleepy and tired, if we lose the battle, it will be a great blow to morale, so we can't be greedy for merit."

"And I just observed that although Liu Yu's subordinates admit defeat very rarely, each of them is very fierce, and it is best to trap them for the sake of today."

"The grain and grass in Youzhou City can't last too long, and Dugu Yan is a narrow-minded person, as long as there is time, there will definitely be suspicion between him and Liu Yu, and at that time, we will be able to defeat the two of them in one fell swoop."

Cao Cao said faintly.

"The prime minister is a good plan." Guo Jia appeared to Fengcheng Cao Cao, but he sneered in his heart.

Now that he knew Cao Cao's plan, of course he would inform Liu Yu as soon as possible.

Soon a carrier pigeon flew to Liu Yu's camp, and at this time he was counting money in the camp tent.

Dugu Yan was settled in gold, and Liu Yu's eyes were almost blind.

Although he knew that gold did not have such a great value in this world, he was still a little excited.

"My lord, a secret letter is coming." Ryuzo walked over with a small note.

After Liu Yu saw it, he immediately laughed.

"Haha, Cao Cao is really scheming, he actually wants to use the method of trapping beasts to deal with me and Dugu Yan, if you don't know, it's really easy to fall into his way."

"But now that you know, then this plan is useless, you go and invite Dugu Yan over, I want to talk to him about it."

"Yes, sir." Ryuzo went down immediately.

"What the hell is going on? Do you want me to make a trip myself? Dugu Yan felt a little dissatisfied with coming to Liu Yu's tent again.

"Just look at this." Liu Yu handed the note to Dugu Yan.

"Oh? This is? I didn't expect you to have people around Cao Cao, it's really not easy. ”

"This Cao Aman is really cunning and cunning, but I'm afraid if he forgets it this time, I'll sort out my armaments during this time."

A smile appeared on Dugu Yan's face, which made Liu Yu a little puzzled.

His smile doesn't seem so simple.

After Dugu Yan left, Liu Yu immediately recruited Long San.

"You go to follow Dugu Yan tonight, this old boy must have something to hide from me, don't act rashly, put safety first, and come back alive."

Liu Yu patted Long San on the shoulder.

"Yes, sir."

Long San went down, and Liu Yu was no longer interested in counting gold, so he began to delve into the machine guns he brought, hoping to build a few more before the big war.

It was a battlefield weapon, but in the end he was disappointed.

"Sure enough, the things produced by the system are not so easy to imitate."

After a busy afternoon and an evening, Liu Yu was also tired.

But he had just laid down when Ryuzo had already returned.

"My lord, I have made a big discovery."

Long San ran to Liu Yu's bedside, and his breathing was a little heavy.

"Tell me, what did you find?" Liu Yu immediately stood up.

"I've been following Dugu Yan today, he was still rectifying military affairs during the day, but at night, he sneaked out of the city and ran to the mountains to kill demon beasts."

"Kill monsters?" Liu Yu frowned.

When these two armies were fighting, how could the commander sneak out of the city to kill the monsters? This matter must be very important to Dugu Yan.

"Okay, Ryusan, you go back first, let's do this today, you have made a great contribution this time."

Liu Yu lay on the bed, thinking about Dugu Yan's purpose until he went to bed.

The next day he woke up groggily.

"No, I'm going to see it myself tonight, or I won't be able to sleep."

Just do it, after inspecting the position, Liu Yu got ready.

Invisibility potions are definitely something to bring, along with some other weapons.

After it darkened at night, Liu Yu drank the invisibility potion, sneaked into the city, and came to the general's mansion.

"You guys give me a good patrol, and you can't let any suspicious people in, do you hear that?" Dugu Yan's voice came in from inside.

Soon, he walked out of the general's mansion alone, and then jumped onto the roof of the house, and ran all the way out of the city.

Liu Yu followed Dugu Yan from a distance, and felt more and more suspicious that this guy was suspicious.

Half an hour later, Dugu Yan entered the mountain.

When Liu Yu entered, he found that Dugu Yan was sucking blood on the corpse of a demon beast.

"What is he doing here?" Liu Yu was taken aback.

However, he soon discovered that after Dugu Yan finished sucking blood, he immediately began to practice his exercises, and his body was shrouded in a layer of blood mist.

He actually practiced by sucking the blood of demon beasts.

"The system prompts, discover a new martial art: Blood Demon Heart Method, is it deduced and included?"

The sudden prompt system sound made Liu Yu jump, but he immediately agreed, and then left.

No wonder Dugu Yan was so happy after hearing Cao Cao's plan, it turned out that he wanted to take advantage of this opportunity to practice, but now he was cheap.

I thought that this kind of peaceful life would last for a while.

But he didn't expect that on the third day, he received military intelligence.

"My lord, Dugu Yan sneaked into Cao Jun's camp alone last night to assassinate Cao Cao, and he almost succeeded, but was stopped by Xu Huang in the end."

Long San said with a look of regret.

However, Liu Yu was very surprised, Dugu Yan's cultivation method was really so powerful? In a few days, he almost killed Cao Cao? If he is allowed to practice all the time, he will not be invincible in the world?

Fortunately, he recorded this exercise, otherwise he would not have known if he would have been calculated by Dugu Yan in the future.

"Okay, now I'm afraid Cao Cao is also going to start cultivating, and this battle has become a cultivation competition." Liu Yu said with a wry smile.