Just like Yoru said. This process is very painful. And made Saeko and Shizuka scream in pain.

ARRRGGGHHH!!!!

"If you guys want to stop, you can let go of my hands." Yoru said with a bit of anxiety.

Saeko and Shizuka saw a face full of worry on Yoru. However, neither of them wanted to be a burden to Yoru. So, they decided to hold Yoru's hand tightly as a sign that they wanted to continue.

Yoru, reluctantly did as Saeko and Shizuka wanted. Actually Yoru didn't want to do all this. But he respected Saeko and Shizuka's wishes, so he continued this process. However, he was trying to control his mana well so they wouldn't be in too much pain.

This process takes a little longer. After enduring the excruciating pain for 2 hours. Saeko and Shizuka were starting to get used to it a bit.

"You guys have multitasking, so I'm sure you're listening to what I'm saying right now. So listen carefully."

"You guys are now trying to gather your own mana. Imagine that you are now breathing. And look for the same feeling as what you were feeling earlier."

Saeko and Shizuka started to focus on their breathing. Even though their bodies feel very hot, they still do all that. With a determination to help Yoru and so that they can stay by his side, the two do the dangerous with full of faith.

"If you can already feel it. Try to move the heat to your entire body."

Yoru helps the two of them a bit by helping them control the mana they gather.

After 1 hour, both began to look calm and not in pain.

"You can stop now."

Saeko and Shizuka stopped gathering and controlling mana. And immediately lay on the bed.

"How are you feeling?" Yoru asked with a little anxiously.

"I feel like my body is so light now. Like, a weight has been lifted. But the pain..." Saeko shuddered at the memory of the pain she felt.

"Obviously. You guys did what you should do in 3 years and you done it in 3 hours." Yoru looks a little relieved to see Saeko can joke a little.

"Yoru. I want sex. Give sex now." Shizuka immediately pushed Yoru and kissed him.

Shizuka's hands immediately tried to take off Yoru's pants. But, unexpectedly by Shizuka. Yoru's hands started to take off Shizuka's panties and started playing with her pussy.

Saeko didn't want to lose and grabbed Yoru's other hand and placed it on her pussy. Shizuka then pulled yoru's hand off her pussy and then inserted Yoru's penis into her pussy in one thrust.

“Aaahhh…” A look of joy was evident on Shizuka's face.

Shizuka started to move her hips and enjoyed the sensation of Yoru's penis in her pussy.

As for Saeko, she was still enjoying Yoru's finger inside her pussy. Since Shizuka was now riding on top of Yoru, Saeko then kiss Yoru.

They then did 3P for half an hour. And ended up lying on the bed with Yoru's finger inside Saeko and Shizuka's pussy.

"You guys have to continue the mana gathering process, so let's finish this now. We can continue later."

"Yoru. I love you." Shizuka whispered and then kissed Yoru.

"Me too." Saeko then also kissed Yoru.

"I'll be out for a while to prepare something."

Yoru then took out her finger from Saeko and Shizuka's pussy.

Saeko and Shizuka then licked his fingers which made him aroused again. But he held back a little and just kissed them both before leaving the room.

***

Outside, every time Yoru passed someone, they looked at him in disbelief.

"What did you do to those two." Souichiro asked Yoru aggressively.

"Not much, I just trained them a little. And maybe. After coming out of that room. Saeko will be stronger than you." Yoru replied and he patted Souichiro on the shoulder before walking away from him.

"Son of a bitch." Souichiro cursed at Yoru. But, unexpectedly, Yoru could hear it and replied to Souichiro's curse.

“This bastard is the one who can save all of you.” Yoru replied and left Saya's house without looking back. But he didn't forget to give Souichiro a finger.

Outside Saya's house, Yoru walk towards a place where he could see the surrounding area.

"This house is like a fortress. It is on a hill and the access road is a bit uphill."

Yoru with farsight in his eyes began to look for where the zombie hordes had gathered.

After a while. Yoru found out where the zombies had gathered.

"It's still 3 pm. We still have about 2 hours. I think this is enough for Saeko and Shizuka to get enough mana."

[Remind. Your skin modification process has reached 50%.]

"Ah, maybe tomorrow I can finish my skin and move on to the eyes."

Yoru looked back at the area and found a bus speeding towards Saya's house.

"Isn't that a school bus? What was the teacher's name again?"

[Shido]

"Ahh yes. That. He already had mana yesterday, can he use it now?"

[Don't know. But the possibility that he now has a skill is quite high. With this world undergoing evolution. Maybe humans are also forced to evolve]

"And one way to do that is to make humans have skills."

[Right. If it like that. You have one more way to increase the amount of mana you have. By killing humans who have skills. You can take their heart and transfer the mana inside into your body]

"Ahhh... What a disgusting way again."

[You also haven't used the core from the messenger you picked up yesterday]

"Ahh... I forgot. I better do it here."

Yoru then. took the Messenger Core from his inventory and started sucking the mana inside.

"The process isn't that difficult. It's even easier than collecting them from the air."

[Right. That's also the reason why many worlds where humans possess mana kill each other]

"System, so you have information about the other world?"

[Yes. You're not the first to become my user]

"Ohh. I don't want to ask about your past. Because I don't need to know either. For now."

[Your mana increased by 50 and mana regen increased by 2]

"Ohhh... that's a lot. System, how much mana God have in them?"

[Depends. If it's just the normal one, about 1 millions. High God around 10 millions. True God around 100 million. It's just a rough number though. There's Spirit that have that around 500 million mana]

"The fuck with that number. To much zero. And you said I could became a God. And what with that spirit. 500 million... Seriously."

[If you do what I say. You can even have an amount of mana that will never run out]

"Ahhh... did you want to make me that strong?"

[Yes]

"But why?"

[With you being a god. I can break free from this prison]

When Yoru have conversations with System, his head receive a lot of pain.

"AAAARRRRRGGGGGGHHHHHH!!!!!"

"My head. Don't tell me"

Not long, Yoru fainted.