"I can handle Stage Four Gastrea as long as I don't have to banish them into another dimension."
"But Stage Five..." Betty frowned. "Based on what you've told me, banishment is the only option."
She had always been confident in her own strength, yet after learning about the Gastrea's abilities, even she found them troublesome.
"It's fine. Stage Five Gastrea are scattered all over the world. Running into one isn't exactly easy." Gojo shrugged. "Just think of them as another kind of Sin Archbishop."
"As long as you can banish them, that's good enough."
"Besides, at least you have a way to deal with them. I don't."
He spread his hands helplessly.
"My Cursed Technique doesn't have any way to finish those things off in one blow."
Whether it was Blue, Red, or Hollow Technique: Purple, all of them relied on overwhelming physical force.
Against a Stage Five Gastrea, they could probably inflict devastating damage, but actually killing one was another matter entirely.
Unless he somehow got his hands on a weapon made from super-grade Varanium, he didn't see a reliable way to finish the job.
"But banishing them doesn't kill them. It's only getting rid of the problem."
Betty spoke calmly before something occurred to her.
"Wait."
"I don't think you should be sending Gastrea into that other dimension."
Gojo blinked.
"Why?"
"Did you forget what's already in there?"
"The Great Rabbit. Regulus. All of them are still trapped inside."
She looked at him seriously.
"What if the Gastrea somehow inherit the Great Rabbit's self-replicating ability?"
Gojo fell silent.
Ordinary Gastrea couldn't reproduce. As long as humanity maintained the current situation and slowly wiped them out over time, the crisis could eventually come to an end.
But if they somehow combined with the Great Rabbit...
That would be an absolute nightmare.
The Great Rabbit was one of the Three Great Mabeasts precisely because of its endless self-replication. Individually, each rabbit was weak, but together they had become one of the world's greatest calamities.
If Gastrea gained that same ability...
Then consumed other Gastrea, split apart again, and multiplied even further...
Even imagining the outcome was enough to make anyone shudder.
"It's fine."
Betty puffed out her cheeks.
"I just won't let them back out."
Then, after a brief pause, she added in a small voice,
"And if they all merge into some horrible monster in there..."
She looked at Gojo with complete confidence.
"Then someday, if we end up in an especially awful world, we can just throw it out before we leave."
"It'll count as cleaning up the world."
Gojo rubbed his forehead.
"I keep telling you to stop watching so much TV. Instead of learning the good parts, you're picking up villain speeches."
"I didn't learn it from TV."
She folded her arms proudly.
"I learned it from manga."
"Maybe read fewer questionable manga."
The two wandered through the wasteland while chatting, continuing their investigation of the Gastrea.
Along the way, they traveled to several different areas, hoping to encounter higher-ranked specimens.
Unfortunately, after searching for quite some time, they found only Stage One through Stage Three Gastrea.
Stage Four and the elusive Stage Five were nowhere to be seen.
Based on everything they'd observed, the overwhelming majority of Gastrea belonged to the lower stages. Stage Three already counted as the backbone of their population.
By the time they finished exploring, both of them had gained a much clearer understanding of the creatures.
Their terrifying regeneration wasn't their only dangerous trait.
Many Gastrea had incorporated characteristics from other animals, evolving entirely new abilities.
Some could spit corrosive acid. Others possessed various long-range attacks.
None of it posed even the slightest threat to either of them.
By the time they'd finished their investigation, it was already well past midnight.
"That's enough for today."
Gojo stretched lazily.
"We should head back."
"I've wanted to leave for ages."
Betty yawned.
"These things look way too much like Cursed Spirits."
"Good timing, then."
Gojo smiled.
"You can spend the next few days studying the local language."
"The writing system here is exactly the same as my world's. There's a good chance future worlds will be similar too."
"I know."
Betty nodded confidently.
"Something this easy won't give Betty any trouble."
The two of them rose into the night sky and retraced their route toward Tokyo.
Neither of them knew that, at that very moment, the entire city had already been thrown into turmoil because of them.
Ever since the war against the Gastrea began, humanity had been losing ground in every conceivable way.
Even their satellites hadn't escaped disaster.
One of the twelve or so Stage Five Gastrea, Sagittarius, possessed attacks capable of striking targets from extreme distances, destroying nearly every satellite humanity had left in orbit.
Only a handful remained.
Among them were several still controlled by the Tokyo Area.
To guarantee the city's safety, those satellites and ground-based radar systems monitored Tokyo around the clock.
Their purpose was simple.
If a flying Gastrea climbed high enough to bypass the Monoliths' protection, the military needed to detect it immediately and scramble fighter jets before it reached the city.
Most of the time, the system found nothing.
Tonight was different.
The instant Gojo and Betty took flight and headed beyond the city, the surveillance satellites locked onto them.
Two human-shaped figures streaked through the night sky at astonishing speed.
Alarms immediately rang throughout the Self-Defense Forces.
The satellite cameras captured both of them clearly.
At first, the operators studying the thermal images assumed the system had malfunctioned.
But the moment the visual feed came through...
The entire command center froze.
They weren't looking at grotesque Gastrea.
They were looking at two perfectly ordinary people.
No mutations.
No wings.
No specialized equipment.
Just a young man and a little girl.
The only impossible thing about them...
Was that they were flying.
Within minutes, reports regarding the pair climbed through every level of command.
At the same time, the satellites never lost sight of them.
The cameras followed them all the way out of the city...
...and beyond the Monoliths.
"Who are these people?!"
"Have they lost their minds? They actually left the protection of the Monoliths?"
Everyone watching the feed was equally shocked and confused.
Flight itself wasn't impossible.
Modern technology had already given humanity aircraft.
That wasn't what stunned them.
The problem was that this world was no longer one where flying guaranteed safety.
Even fighter jets capable of reaching several times the speed of sound rarely dared to take off.
The ground belonged to the Gastrea.
The skies were little better.
Countless flying Gastrea patrolled the air, attacking anything alive the moment they detected it.
That was why any expedition outside the city required military escort.
Without protection, nowhere was safe.
As expected, once Gojo and Betty left the city's boundaries, the satellite feed showed Gastrea swarming toward them.
Those on the ground could only watch helplessly or launch long-range attacks that couldn't possibly reach them.
The flying Gastrea were another story.
One after another, they rushed toward the pair.
Then...
Everyone watched the impossible unfold.
The white-haired young man and the little girl casually waved their hands.
Each approaching Gastrea died almost instantly.
The scene only became more unbelievable once the pair stopped in the wasteland and began calmly studying the monsters as though conducting field research.
When Gojo unleashed Blue and crippled an enormous group of Gastrea with a single attack...
Many people genuinely felt their minds go blank.
Until now, humanity had only three reliable ways to eliminate Gastrea.
Overwhelming firepower.
Weapons made from Varanium.
Or sending the Cursed Children into battle.
Every one of those methods carried tremendous risk.
Otherwise, humanity would never have been pushed to the brink of extinction.
Yet tonight...
They had witnessed something that completely overturned everything they believed.
Humans could fly through the sky.
Humans could wield supernatural powers.
Even the terrifying Gastrea that had plagued humanity for years looked utterly powerless before them.
Before long, news of Gojo and Betty spread among Tokyo's highest authorities.
"Lady Seitenshi, this is an emergency."
Outside an elegantly furnished room, a young man in the white uniform of the Guard Captain knocked firmly on the door.
"I understand."
After a brief silence, a gentle voice answered from within.
It was soft and calm, carrying the faint weariness of someone who had only just fallen asleep.
Moments later, the door opened.
A slender young woman stepped out.
Anyone familiar with Tokyo's leadership, including Rentaro or Kisara, would have recognized her instantly.
She was Seitenshi, the supreme ruler of the Tokyo Area.
"Captain Yasuwaki."
She looked at him.
"What happened?"
Takuto Yasuwaki, commander of her personal guard, bowed respectfully.
"The Self-Defense Forces have just sent an urgent report. It requires your immediate attention."
As he spoke, he produced a tablet and handed it to her.
Seitenshi accepted it, worry already filling her expression.
Being awakened at this hour could only mean one thing.
Something serious had happened.
Given the current state of the world, her first thought was another Gastrea assault.
She sat down on the nearby sofa and switched on the screen.
The moment the satellite footage began playing...
She froze.
Gojo and Betty soared through the night sky.
Anyone seeing the footage for the first time would have been stunned.
Then came the scenes of the pair effortlessly dispatching Gastrea before casually examining them afterward.
"...Who are they?"
Although still young, Seitenshi had reached her position through intelligence far beyond her years.
She immediately understood the significance of what she was seeing.
If this power could somehow be shared with others, just as mechanical enhancement technology had been...
Then humanity would face the Gastrea with far greater confidence.
Their chances of survival would increase dramatically.
Perhaps there would finally be hope for the future.
"We don't know."
Takuto shook his head.
"We've searched every database available."
"There isn't a single matching record."
"It's as if they appeared out of nowhere."
"We don't know their names, where they came from, or even their ages."
Hearing that, the tension in Seitenshi's face eased slightly.
Compared to a full-scale Gastrea invasion...
This was excellent news.
"Can we locate them?"
She lifted her eyes from the tablet.
"Yes."
"The satellites are tracking them continuously."
He pointed toward the screen.
"They're already on their way back."
"In that case..."
Seitenshi looked at the two figures flying across the night sky.
"Contact them immediately."
"If possible, I'd like to meet them myself."
Takuto adjusted his glasses.
"My lady, we know nothing about their origins or motives."
"If they have ulterior intentions, or if another faction sent them to target you..."
"I can't recommend allowing direct contact until we've learned more."
He paused briefly.
"Rest assured, we'll arrange for someone else to approach them first."
Seitenshi remained silent for several moments before nodding.
"Until we have proof they're hostile..."
"Treat them with the utmost courtesy."
She looked once more at the images of Gojo and Betty.
"The abilities they possess are exactly what humanity needs."
"If they're willing to cooperate with us, the burden of fighting the Gastrea could be reduced enormously."
"Understood, Lady Seitenshi."
Takuto bowed deeply.
With that, he turned and left the room.
The moment his back faced her, however, a different light flashed behind his lenses.
Ambition.
Desire.
The power those two displayed had surpassed mechanical enhancement.
It had surpassed even the Cursed Children.
No matter what it took...
He wanted to obtain that power for himself.
That night, neither Gojo nor Betty had the slightest idea that their brief excursion had already set hidden forces into motion throughout Tokyo.
The pair were still making their way back toward the city, with quite some distance left to travel.
As they flew through the night, they were discussing something far less dramatic.
Specifically, whether they should hire Betty a private tutor after waking up the next day.