Chapter 8: The Big Fish
"Simple Domain—as the name implies—is a type of domain technique."
"It automatically performs reflexive counterattacks against anything that enters a certain range around my body."
Although she wasn't allowed to teach Ren the technique itself, there was no problem with explaining its effects in general terms. Seeing the keen interest in his eyes, Miwa spoke quite openly.
So that was how it worked.
No wonder she hadn't needed to look at the enemy. If the technique truly functioned as a fully automated reflex system, visual confirmation was unnecessary—if anything, visual input might even interfere with the execution of the automatic counter-response.
Absolute defense within a fixed range.
Absolute counterattack.
Guaranteed hit.
…Interesting.
The principle behind it must be that layer of cursed energy distributed around her body—using cursed energy itself as a precise sensing medium.
As Miwa explained, Ren listened while quietly piecing together the information with what he had personally perceived earlier.
"'Absolute' might be overstating it," Miwa said modestly, shaking her head after hearing his assessment.
"It's still limited by the user's physical capabilities. If you don't have enough strength, or your speed can't keep up, you still won't be able to block the attack—or land the hit."
"But," she added, straightening her posture slightly with a hint of pride,
"it is a pretty practical technique."
Ren smiled faintly.
He knew it was just humility.
If you were facing an opponent whose strength completely overwhelmed yours—who crushed you in power, speed, and reaction—then no technique, no matter how refined, would save you anyway.
All in all, this Simple Domain was undeniably valuable in real combat—and precisely because of that, it was also worth studying.
Although Ren's Limitless Probability Technique could likewise guarantee absolute hits or absolute evasion, probability manipulation demanded extremely fine cursed energy control and came with enormous overall energy consumption.
By contrast, judging from what he had just observed, Simple Domain appeared to have a far lower activation cost…
"Alright, alright—wrap it up," Mai said, tucking her revolver back into the thigh holster and clapping her hands as she turned to leave.
"Not bad," she added while pulling out her phone to check the time.
"We're getting off an hour and a half earlier than usual classes. Call it a fair trade."
"So how about it?" she continued casually.
"Miwa, want to swing by Isetan and check out the new cosmetics?"
"N–No, no," Miwa waved her hands quickly.
"Um… I still have some things to take care of later. M–maybe next time, Mai."
Next time—which usually meant never.
Miwa did envy the dazzling displays of luxury cosmetics at Isetan.
But she also had two younger brothers to support. As the eldest, she carried the weight of the household on her shoulders.
Extravagant expenses were things she had learned to decline politely.
"Wait."
Ren glanced at the two who were clearly about to leave, then looked toward the corner of the factory where a fish-like cursed spirit was slowly emerging.
"That's it? We're done already? What about over there—"
"Those small fry aren't worth worrying about," Mai waved dismissively.
"These cursed spirits don't even qualify as Grade 4. They pose no real threat to ordinary people. And there are tons of them. If every single one had to be exorcised, every jujutsu sorcerer in the world would've died of exhaustion long ago."
So that's how it worked…
Ren watched as countless tiny cursed spirits continued to ooze out from the shadows, gradually agreeing with her assessment. If he really had to eliminate them one by one, it would be a hassle.
The most efficient solution he could think of was simply leveling the entire building with cursed energy-infused attacks.
He turned and followed the two of them back the way they came.
"But… won't that cause problems?" he asked, scratching his head as they walked.
"What if they start devouring each other—big fish eating small fish, small fish eating shrimp—and end up breeding some absurdly powerful cursed spirit?"
"What is this, Pokémon?" Mai shot back reflexively.
"You think they level up through battles?"
Then she paused and added,
"…Though it's not impossible."
"…Huh."
"But that's not necessarily a bad thing. Generally speaking, once a cursed spirit reaches Grade 2 or 3, it draws attention. Jujutsu High will dispatch sorcerers to eliminate it."
"So even from an efficiency standpoint, letting cursed spirits fight among themselves and then killing the winner is more efficient than clearing them out one by one."
…That actually made a lot of sense.
Ren wasn't the argumentative type. Since her reasoning checked out, he simply kept walking without further objection.
"Anyway, that's just industry standard," Mai concluded.
"Write it down in your newbie memo—unless you want to work yourself to death someday."
"Unless," she added with a teasing smirk,
"you, the 'Twelvefold Sorcerer' with twelve times the power of a normal one, think you should also take on twelve times the workload."
"Absolutely not," Ren shook his head vigorously, picking up his pace.
"Off work! We're clocking out righ—"
Before he could finish—
BOOM!
A thunderous explosion erupted overhead. A violent gust of wind howled past the back of his head.
"Get down!"
He barely had time to shout as he leapt aside—
A massive machine tool shot past his vision and slammed into the opposite wall with a deafening crash. Most of the steel structure embedded itself straight into the concrete. The impact sent violent tremors through the floor, and dust and debris rained down from the ceiling.
"Miwa! Mai?!"
Two sharp coughing sounds answered him from within the smoke—enough to tell him they hadn't suffered serious injuries.
He spun around, eyes snapping toward the direction the machine had come from.
High above, the ceiling had been torn open into a massive hole.
Amid swirling dust and rubble, a gigantic creature—resembling a grotesque fusion of lizard and human—was perched atop a heap of twisted steel and concrete. Its thick, two-meter-long tail slammed against the ground repeatedly, producing booming impacts.
Spiderweb-like cracks spread across the hardened floor. The entire level shook as though in the grip of repeated earthquakes.
"So this is… the big fish?"
Ren stared up at the monster's brownish-red reptilian head, which nearly brushed the ceiling, murmuring to himself,
"Isn't it… a bit too big?"
The creature opened its massive maw, rows of jagged teeth exposed, and unleashed a thunderous roar.
With it came a surge of cursed energy—far denser, far more oppressive than even the ape cursed spirit from before.
"Watch out!"
Miwa dashed forward in a blur, positioning herself in front of Ren.
"Th–This cursed spirit's grade is definitely—
definitely not just Grade 3!"