Ye Lei took out 10,000 crystal cores from his spatial storage and placed them in his palm. Looking at the mountain of crystal cores in front of him, he felt a little excited, but even more nervous and worried.

After all, absorbing the energy of 50,000 crystal cores at once was too risky. If he couldn't withstand the massive energy impact, he might suffer from qi deviation or even die from his body exploding. After careful consideration, he decided to try absorbing the energy of 10,000 crystal cores first.

Ye Lei looked at the pile of yellow or blue crystal cores, which represented different levels of zombies.

However, for Ye Lei now, the color of these crystal nuclei is no longer important; they merely represent differences in the amount of energy.

Ye Lei gently closed his eyes, concentrated his attention, and focused his mental energy to the extreme. The crystal core in his hand gradually emitted a faint white light, which grew stronger over time until his entire hands were enveloped in a dazzling white light.

Ye Lei frowned slightly, focusing more on his mental world and guiding the powerful energy. Under his control, the white light finally converged into a long river of energy, flowing continuously into his body through his nostrils. After a while, when the last ray of light disappeared, the crystal core in his hand had also vanished.

Ye Lei also felt the energy of the crystal core surging through his body, impacting every cell, as if it didn't want to be absorbed.

Ye Lei frowned slightly. He realized that there were a lot of Corpse Kings in this pile of crystal cores. In that case, the energy inside the crystal cores was too strong, making it difficult for him to fully absorb it in a short time.

Therefore, he decided to store this powerful energy in his dantian and slowly digest and absorb it. As time went by, Ye Lei could feel his body gradually adapting to and absorbing the energy of the crystal core.

However, the process took much longer than he expected. After about half an hour, Ye Lei finally absorbed all the energy in his dantian.

At this moment, he felt a strong power surge into his heart, as if every cell in his body was being nourished and growing. Ye Lei closed his eyes and felt the changes in his body.

He found his muscles becoming stronger, his bones more solid, and even his breathing becoming deeper and more powerful. This exhilarating feeling intoxicated him and gave him an unprecedented sense of confidence and strength.

However, no system notification of power upgrade was received, indicating that the energy required for further power upgrades will be even greater.

Ye Lei did not give up. He absorbed the energy of another 10,000 crystal cores using the same method. However, this time, he did not store the energy in his dantian, but absorbed it all directly.

There was still no system notification about upgrading his abilities, which puzzled Ye Lei. Was upgrading his abilities really that difficult now?

He took out another 10,000 crystal cores from his spatial storage. Due to the continuous energy absorption, his body was clearly unable to withstand it. However, he gritted his teeth and stored the energy in his dantian, not giving up easily.

Time ticked by, and cold sweat began to bead on Ye Lei's forehead, his body trembling slightly, but he persevered.

Finally, when the last crystal core was absorbed, Ye Lei felt a powerful surge of energy welling up in his heart, and his superpower seemed to have made a new breakthrough.

Sure enough, the system's voice echoed in my mind:

[Congratulations, host! Your Earth-type ability, Rock Rain, has been upgraded to Landslide and Earth Shattering!]

Ye Lei was overjoyed. It seemed that only through continuous attempts and efforts could he upgrade his superpower.

Landslides and earthquakes? That sounds pretty exciting. Let me tell you about it.

The "landslide and earthquake" ability not only produces a barrage of rocks, but can also flatten small mountains up to 50,000 cubic meters in size.

Wow! Not bad at all! I wonder how it will be upgraded next?

[The highest level of earth-based superpower, "The Foolish Old Man Moves the Mountain," can move a small mountain of 100,000 cubic meters to your desired location; its power is truly earth-shattering!]

The Foolish Old Man Who Moved Mountains? Just the name sounds incredibly impressive! It seems he needs to collect the crystal cores as soon as possible. As for the remaining 20,000 crystal cores, he decided to keep them for now.

He noticed that Red Boy and Xiu Xiu's demand for crystal cores had been increasing recently, and perhaps their superpowers were gradually upgrading and breaking through. After all, they couldn't run out of these "snacks"!

Although the upgrade process was fraught with difficulties and challenges, Ye Lei knew that this was just the beginning. As his ability level increased, the energy required would also increase. Therefore, he had to continuously search for more crystal cores to enhance his strength.

Ye Lei glanced at his watch; it was getting late. He had originally planned to rest early, but he had promised Xu Jiao he would go to her room, so he couldn't break his promise.

He cautiously left his room. The corridor was quiet, without a sound. It seemed everyone had already returned to their rooms to rest. Ye Lei tiptoed to Xu Jiao's door, feeling somewhat uneasy.

The door to the room was ajar, which surprised him. It seemed that Xu Jiao had been waiting for him, but it was so late, she was probably already asleep. Ye Lei gently pushed the door open, trying not to make any noise.

The door slowly opened, and he saw Xu Jiao lying on the bed. Her breathing was even and soft, and she had obviously fallen asleep. Ye Lei couldn't help but breathe a sigh of relief. He didn't want to disturb her rest.

He entered the room and gently closed the door. A faint fragrance filled the room, making people feel peaceful and comfortable. Ye Lei walked to the bedside and gently sat on the edge of the bed.

Looking at Xu Jiao's face, a warm feeling welled up in his heart. Her face looked so peaceful and beautiful in the dim light. Ye Lei couldn't help but sigh that Xu Jiao was a really special girl. She could always bring him peace and comfort.

He sat there quietly, enjoying the peaceful moment. He knew they had a lot to do tomorrow, but for now, he just wanted to stay by Xu Jiao's side and protect her dreams.

Time passed quietly, and Ye Lei felt himself getting tired. He stood up gently, preparing to leave the room, but before leaving, he couldn't help but gently kiss Xu Jiao's forehead to express his gratitude and blessings to her.

Then, he quietly walked out of the room, closed the door, and returned to his own room. He knew that tomorrow they would face new challenges and difficulties together, but now they could rest peacefully because they trusted and supported each other.