Heaven-defying Upgrade System

Although Si Yin did not have a magic treasure Flying Sword, she had something that allowed her to fly. This thing was like a green worm, but it was much smaller than the green worm. It looked like a miniature green worm, but it was also in the shape of a bird. Si Yin's flying device looked more like a small green bird.    

    

The two of them sat in the belly of the flying device. What shocked Liu Fei was that... This small flying device actually had something to control the direction! It was like the handle of a motorcycle, and Si Yin skillfully controlled it. She brought Liu Fei along as fast as lightning in this world filled with branches and vines.    

    

The speed at which they moved was actually not any slower than Flying Sword!    

    

Liu Fei was curious as to how it ran. But he quickly thought that perhaps this thing was similar to the Sacred Origin Spear that Si Yin used. It was also provided by that mysterious energy.    

    

Liu Fei could not help but be stunned!    

    

Putting aside War God Continent, if this were to be brought to Earth, wasn't it just a new type of energy? Not only did this type of energy look very powerful, it was also green in nature! However, Liu Fei was just thinking about it. After all, he didn't know what this thing was.    

    

"Don't tell me you don't even know about such a precious thing as the Green Source Crystal Stone!" Si Yin controlled the "little bird" flying device as she turned around to ask Liu Fei, "Are you really from this world?"    

    

Liu Fei only said that he came from another world and did not say that he was not from this world. If he said it, no one would believe him. So he rubbed his head in embarrassment and said, "The place I came from is very far away. I have heard about the things here. I have never seen them before."    

    

Si Yin could not help but smile and said, "You go and fool the child! Anyway, what you said is not very reliable..." Following that, she took out seven Green Source Crystal Stone and handed it to Liu Fei. This should be for you. That Lava Warrior was defeated by you. You have contributed the most. "    

    

Liu Fei waved his hand and said, "You should take this thing back. I don't want it. Just treat it as living with you. I will give you the rent!"    

    

"Hmph, you are generous enough." Si Yin said, "I did not expect that you would not be moved by these seven pieces of Green Source Crystal Stone. Forget it. It is too expensive to treat it as a accommodation fee. Since you do not want to take it, I will keep it for you first."    

    

As Si Yin spoke, the speed of the aircraft suddenly increased again. Liu Fei could only feel light flashing in front of his eyes. If it wasn't for the fact that he had already reached the seventh level of the Spirit Dan Stage... I'm afraid I'm gonna get dizzy from this thing. At the same time, Liu Fei's eyes swept across this mysterious world. He discovered that most of the people here were ordinary people, but there were still many powerful people present. However, they were much stronger than ordinary people. Not like cultivators, but as if they were born with such power.    

    

Si Yin's cultivation base was still unknown for the time being, but Liu Fei could feel that if the people here were to cultivate, their cultivation base would increase very quickly.    

    

After a while, Si Yin stopped in front of a huge tree. After that, she took back her flying device. Liu Fei took this opportunity to look at the big tree in front of him. It looked more like a towering building. The outside was surrounded by vines, and from the looks of it, there were many small windows on the tree trunk. That should be the place where the people lived.    

    

However, what surprised Liu Fei was that the center of the tree had obviously been hollowed out, but it was still growing very vigorously. Liu Fei, who could not understand the reason, found it very novel!    

    

"It's going up!" Si Yin said to Liu Fei, and then her figure flashed. She stepped on the fallen branches and vines and flew up. Liu Fei followed closely behind. The two of them drilled into a hole that looked like a tree hole, and the hole fluctuated. After entering, Liu Fei's field of vision suddenly opened up. The space inside was too big! Furthermore, the decorations inside were very unique.    

    

This should be Si Yin's room. It was very big and spacious. Other than the entrance, there were no ventilation vents like windows. However, Liu Fei did not feel stuffy at all inside. It was as if there was an invisible airflow blowing from below. It was very magical.    

    

"This place is very comfortable!" Liu Fei casually found a chair made of vines and sat down. That chair looked very green. It was like a fresh tree. Sitting on it was more comfortable than sitting on the sofa. Then he looked at the decoration here. Everything looked like it was living in nature. He asked, "How much is the house here? Do you live here as you wish? "    

    

Si Yin smiled and said, "Do you think this place is free? To tell you the truth, if you want to buy a house like this, furthermore, the house that I live in is considered a very low grade one. However, as long as you don't mind it!"    

    

How could Liu Fei mind? Sitting here was more comfortable than lying down. If he had the chance, he would definitely build a house like this once he returned to the Martial God Continent. However, Liu Fei seemed to have thought of something and said in a slight daze, "You only need ten Green Source Crystal Stone to buy this house. What's the value of that Green Source Crystal Stone?"    

    

After Si Yin returned, she changed into her revealing attire. She found a white muslin skirt from somewhere and wore it on her body. Rather than calling it a muslin skirt, it would be better to say that it was a dress made of extremely fine silk. It was also not completely white and it faintly revealed a bit of green. Wearing it on Si Yin's body, her body seemed to be faintly discernible inside. It was fascinating!    

    

Furthermore, when Si Yin sat beside Liu Fei, her body emitted a faint fragrance. It did not smell like the fragrance of flowers, but like the pure fragrance in the air after spring rain.    

    

With such a beautiful woman sitting beside him, Liu Fei almost could not control himself. Fortunately, he had a certain level of mind cultivation. He slightly restrained his mind and looked away, so Si Yin did not take his soul away.    

    

"Let's put it this way. One Green Source Crystal Stone can be exchanged for ten green energy crystals, and one green energy crystal can be exchanged for ten green energy crystals." Si Yin knew that Liu Fei did not understand this world very well, so she simply introduced it to him.    

    

Liu Fei nodded slightly, then said, "Green Source Crystal Stone should not be the most expensive thing, right?"    

    

"I can't tell. You are quite smart." Si Yin smiled and said, "That's right. The Green Source Crystal Stone may be a very precious thing to me. But it was not the most expensive thing here, because ten Green Source Crystal Stone. It can be exchanged for another Green Source Polar Crystal. "    

    

"So that's how it is!" Liu Fei nodded. At the same time, he thought to himself, in this secret realm, the Green Source Crystal Stone was equivalent to a cultivator's Spirit Stone. If his guess was correct, the energy of their cultivation... It was also obtained from this Green Source Crystal Stone.    

    

After Liu Fei understood this, Si Yin moved closer to him and said, "Young Master, you are very smart and your cultivation is not bad. Why don't you teach me some skills?"