652. Grandpa got OP

Rei was an AI Robot invented by Byakuya Ishigami, Senku's father. This was a project Byakuya had worked on for a long time and Senku had seen it too. It was present during the petrification event and made its debut to the astronaut crew soon after, revealing itself as version 37, a much more rounder and slicker version. It was later revealed that while Rei had the brain-power of 60 smartphone boards and was filled with useful scientific knowledge, it lacked common-sense protocols and human biology information, such as average human life spans.

Rei was pivotal in returning the astronauts to earth, providing the necessary scientific data and doing all the necessary calculations and simulations in order for the Souyz Module to land safely in an appropriate position. Before they all left Rei, Byakuya, with a sorrowful expression, told Rei that it is his friend and he will one day return for it.

Byakuya's promise was actually a lie. The astronauts needed all of the station's fuel to go back down on earth, and the International Space Station would, on its own, burn into the earth's atmosphere in about a year from the current date. Byakuya knew all that and never intended to come back for Rei. The promise was intended for the little robot to pass on in peace.

Rei instead took Byakuya's promise literally and took it upon itself to maintain and keep the ISS in orbit until Byakuya's return. To that end, it modified itself to first fix the solar panels by attaching itself to the space station's arms. When it found out that the astronauts used all of the station's fuel, it found a way to modify the food they left behind into fossil fuel to return the ISS back into its original orbit. And when that ran out, it modified the station's engine to be hydrogen-powered.

At some point, Rei discovers that there was something wrong with its brain. Of the 60 smartphone boards inside it, 12 had ceased functioning. This was because the high energy particles coming out of the sun can burn delicate circuitry. Not to be one to give up, it used the station's computer circuits to upgrade its brain with the capabilities of 1'000 SP (smartphone points) to match up to its upgraded functionality.

20 years after the petrification event,

~I wonder how Byakuya is doing.~ Rei wondered

For the next few years, Rei kept on fixing the ISS and also itself by going out for resource hinting. He found all the remaining satellites and used them.

42 years after the petrification event, Rei realised that Byakuya must not know it was still OK and in space, so it decided to make a light signal to show Byakuya where it was in order to him to return. Unfortunately, it was too late.

The first light signal Rei broadcasted was the last thing Byakuya ever saw. Realising his little robot friend was still waiting for him aboard the ISS in space, Byakuya cried as he lay down dying alone in the river, unable to tell anybody that his little robot friend was still alive.

Meanwhile, Rei, not knowing that Byakuya had just died because it lacked knowledge of human biology, decided to show the light signal whenever it passes over the place Byakuya landed, but only once a year because of the high energy cost it had.

200 years after the petrification event, Rei noted how much greener the earth looked. It then witnesses Mount Fuji erupting, turning a huge part of the formerly green land grey. At the same time, it witnesses an asteroid hit the earth. The asteroid landed in Rome and turned the city into a 25km crater. It also caused severe damage to the ISS and Rei was having a really tough time with the repairs. The asteroid impact had a severe ecological impact too, turning the entirety of Europe grey and ushering in a new ice age. Rei hoped Byakuya was okay and that he kept himself warm as he lighted up the signal once more.

Time flew by for the earth and the ISS. The robot witnessed numerous Mount Fuji eruptions and wondered if it could stop them. It witnessed Byakuya's island growing larger due to an earthquake and it replaced the solar panels of the ISS for the 50th time. Rei wondered when would Byakuya return as it continued fixing the space station.

3200 years after the petrification, Rei discovered that a meteor was heading towards earth, set to strike Japan in 500 years. The meteor was 40km in diameter and weighed 300 trillion tonnes. Its destructive power was calculated to be 200,000 times more than the last one. Should it hit the earth, not only would Japan get wiped out, but all of Earth's oceans would evaporate and all life on earth bigger than 1cm would go extinct. The entirety of the earth would become grey.

Rei, now branding itself an Ishigami, as the surname of Byakuya, decided to go crafting to prevent the meteor impact in order to protect Byakuya and the rest of humanity so that they may return. It created a space factory that manufactured 4,000 hydrogen bombs which, 350 years later, got simultaneously launched towards the meteor. As the missiles hit the meteor, the explosions became visible on Earth, and Senku, in his petrified state, also saw it but couldn't understand its meaning.

The operation was successful and the meteor impact was averted, but in doing so, Rei sacrificed a big part of the ISS and a huge chunk of its gathered resources. It could no longer fix or upgrade itself and it was in a really bad and beat-up shape. Rei still saved the light signal though and was still determined to keep lighting it, despite the energy cost it had.

3,572 years after the petrification, Rei gathered up whatever scarce resources it found around earth's orbit and constructed a giant robot, which, in actuality, was a 3D printer. Knowing that its end was near and that it would soon cease to function, Rei constructed a set of instructions, made out of physical discs, set to last millions of years, which would guide the 3D printer into rebuilding both the ISS and Rei directly in space, so that Byakuya could return to it after the original Rei and the ISS are gone.

As the memory of people faded due to memory damage by solar radiation, Rei set the 3D printer into motion. As it laid down, about to cease function, it wondered how many years humans live and if the fact that the earth was now green holds any significance. It wondered if Byakuya would return for it tomorrow.

It decided it was best not to know these things because waiting for it was a reason to stay alive. It then recalled its very first memory, that of Senku commenting on how sad and lonely Byakuya must be to make a robot girl model. Rei wondered if Byakuya was lonely and if that's a bad thing. Its final thought was that there was still meaning in a lifetime of waiting.

3,718 years after the petrification event, on the very day Senku was revived, the reconstruction of the ISS was complete and Rei was reactivated inside a new body. The new body resembled that of the robot girl "Rei 01" model Byakuya had in his office, and was much more humanoid in appearance. The newly rebuilt ISS now resembled a space city more than a space station. Still being beholden to Byakuya's promise, Rei got back to sending the light signal.

Back on Earth, Senku saw the light coming from the ISS. The thought passes through his mind that it might be the International Space Station, but he immediately dismissed it. Chrome, on the other hand, notices it and also wrote it down, but left it to it.

The little robot, now a very intelligent humanoid AI, kept on waiting. Wondering if Byakuya also misses her as she missed him. Her only wish now was to stay alive until the time comes she meets her maker again.

It was again the time of the day when the space station passes over the location of the island. Rei decides to send the light signal as always, once a year. However, she suddenly sees something coming up from the surface of the planet.

~Is Byakuya coming for me?~ she couldn't help but get a little excited. An emotion, new to herself.

She excitedly went to the entrance she had specifically made so Byakuya or other humans could enter. She didn't know much about human biology, but she knew that this thing was very important in ISS.

*KNOCK KNOCK*

Hats knocked. But no one opened the door. So, he opened it himself and went in. He had already set the satellites before coming here.

But once he entered, he was left in shock. Not just him, Rei was left in shock too. Rei only knew what Humans looked like, not cats. So for Rei, Hats was a possible threat.

While Hats quickly sensed that this nude girl was actually a machine, just human-like. But, she was giving expressions of a human. Hats knew a lot of androids in Phixheim so this was not surprising to him.

"Hey, little girl. I am Hats. Have you been showing that light signal?" Hats asked kindly.

Rei nodded, "Are you from down there? What are you?"

"Haha, yes, I am from there. We saw the light so I decided to come and check up on you. Why didn't you yourself come down to heart?" He asked.

"Because Byakuya Ishigami told me he would come back here." She replied.

Hats raised his eyebrow, quickly guessing what had transpired. "What? You've been waiting here for 3700 years? Child, humans can only live up to 120 years max."

Rei was shocked and saddened. Her shoulders fell in disappointment. "Then... he is dead?"

"I'm afraid so, yes. But, Byakuya and other astronauts were able to start a family there. There is a whole village of their descendants. There is also the son of Byakuya, Senku, alive. I think you do not know about what happened on earth. Let me show you. You also seem to be lacking in biological knowledge," Hats deduced. He used magic and materialised a USB drive with all valuable knowledge.

"Here, scan this. You will know everything." Hats gave it to her.

Rei was innocent and didn't know how cruel people can be. She simply stuck the USB drive in her arm, without checking it externally first.

Immediately, Rei found out about the petrification, life of Byakuya, what happened to humanity, human nature and also the biology. But she saw a problem.

"Why are you not in this information? There is no mention of a talking cat?" She asked.

"Kid, I am not a simple cat. You can say that I am an alien. I just came here to sightsee. I will leave soon. Now, do you want to come with me to earth?" He asked.

Rei looked around at the new ISS. "What about this place?"

"Don't worry, I will send someone to maintain it." Hats assured her. He also notified an Android in Phixheim to come here to ISS.

"Okay, how will we go down? We need to make a rocket." Rei asked as she didn't see any aircraft.

"Kid, we will fly." Hats quickly grabbed her and dragged her out.

"You also need some clothes." He muttered and materialised some clothes on her.

Rei was internally a bit excited about finally going to the planet she had been seeing for so long. Though there was still some sadness lingering, but the prospect of meeting Senku again made the sorrow lessen a little.

...

Phixheim,

Olivia had just found a letter in Ajax's room after she called for him multiple times.

"Mom, Grandma, don't worry about me. I, Thea and Hats are going out for an adventure. We will return soon." These were the words in the letter.

But, after looking for him in the Dragon Ball world, they realised that by 'going out' he meant going to another universe. But they had no idea where he went.

Just at that time, Alexander arrived.

...

Special Planet,

Alexander had drowned himself in his physical training this time. He had too many powers and ways to fight and that was a bad thing according to him. He didn't need 100 different types of energy laser beams. He needed 1 powerful laser with the strength of 100 of his attacks.

So, he worked to combine his attacks and powers into one and proceeded to train them to the max level so they would become instincts. This way he won't have to think while fighting.

His power level as compared to God kept on increasing by seconds. From 70 per cent, it reached 80 just by mastering Omniscience. Then, with more training, his power level reached 85 per cent.

Now, he was possibly only below God in terms of power. He didn't think about Zulrak though. That would only be found out when he fights him. But, he had decided he was going to at least get to 90 per cent before he starts a full-scale attack from his side and take back the whole omniverse region currently ruled by Zulrak.

~I wonder how much time has passed.~ He though and took out a watch he had set up. It showed how much time passed in Phixheim. To his shock, 5 days had passed there.

This meant that Alexander had been training for 7.2 Billion years. ~This... I didn't even feel it. I guess I'm getting too old now. Well, I am missing my family too.~

He immediately went out.

*Pop*

...

Alexander heard Olivia getting worried about Ajax and Thea.

"Don't worry, they are fine," Alexander assured her.

She looked back. She noticed a change in aura and body of Alexander. He looked like... god... she couldn't pinpoint it but Alexander seemed different.

"How do you know that?" Olivia inquired.

Alexander went ahead and hugged his wife. Then he took a long breath, "I know, I know everything Oli. Past, present, future. Ajax is just having fun, Thea is also enjoying. Moreover, Hats is there."

As soon as she hugged him, she felt he had gotten thinner, "How long did you spend there to get so thin?"

"7.2 Billion years. What? Did I get more handsome?" He asked jokingly.

She lightly punched him, "Thea and other kids were missing you so badly. But, I guess you had a very bountiful time on that planet?"

"Yes, Oli. It helped me a lot. Now, let's go out and meet everyone." he said and walked with Olivia. His hand was on her waist, but it was slowly falling down.

Olivia quickly slapped it, "Huh, did your training make you a pervert?"

He chuckled. "Hehe... oh no no, I was just appreciating my beautiful wife. Let's go. I'm hungry... for food of course."

[A/N: I really liked the whole story of Rei, the robot, so I added it. It single-handedly saved the whole earth while waiting for its friend's return. Rei will probably go to heaven someday.

Anyway, Alexander's all ready and powered up for DC arc.]

[You can see Rei on my Discord - https://discord.gg/DgHkrAn OR see them on Instagram - https://www.instagram.com/mister_immortal_novel]

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