Became a Failed Experimental Subject Chapter 48

Ch.48 Another Monster

“Fuck, that damn monster bastard!”  

Crash! An A-rank hero, having just returned from dispatch, kicked a trash can in anger.  

And for good reason—this was already his fifth dispatch today.  

Yet, despite responding each time, he hadn’t even caught a glimpse of the monster responsible, let alone engaged it. It would’ve been stranger if he wasn’t furious.  

The Black Cat was a Despair-class monster with a unique ability to deceive the monster alert system.  

At the same time, it was a mutant that didn’t hunt humans… Or so they had mistakenly believed.  

A monster that, as long as there was a hero stronger than itself, would maintain a friendly facade—until it was confident it could completely shake them off.  

“Why is the Black Cat acting like this now?!”  

“It’s not acting now—we’ve just been stupidly fooled this whole time.”  

“It’s not an awakening. It’s revealing its true nature.”  

The Black Cat was darting across W-City at an absurd speed, hunting and devouring humans.  

Three days had passed since the Black Cat began its hunt, and the death toll had already reached around 500.  

And that was with Starlight flying at top speed to minimize the damage.  

“For not being able to catch a Despair-class monster in three days, the damage is still relatively low…”  

“It’s still a miraculously low number for a Despair-class, but it’ll keep rising… Sigh…”  

Each shelter could hold a maximum of about 50 people. The fact that Starlight had failed to arrive on time ten times already meant…  

From the moment a shelter was breached to the time it took to dig deep into the ground—just a little over a minute.  

If Starlight arrived within that window, most civilians could be rescued, leaving only a few injured behind.  

And then, into the next shelter they went… Only to tremble in fear of death again.  

The civilians’ resentful, terrified stares as they were herded back into shelters crushed the morale of every hero.  

“Stop with the defeatist talk!”  

“What else can we do? That bastard was in District 2 one minute, then popped up in District 7 the next, and before we knew it, District 11!”  

“Even when Starlight manages to land a few hits, it just comes back completely fine… We’re the ones getting worn down in this war of attrition. What the hell are we even buying time for?!”  

“An S-rank hero couldn’t catch it before, and now you think charging at it will work…?”  

The situation felt like a game of tag between Starlight and the Black Cat that had spread from one district to the entire city.  

The Black Cat, now overwhelmingly faster, would vanish and reappear in entirely different locations, crossing from one end of W-City to the other to hunt humans.  

Its speed far exceeded Starlight’s, leaving the A-rank heroes unable to even catch its tail.  

Their only goal was to buy time until Starlight arrived, but even that was becoming exhausting.  

“There’s no way… This is…”  

“We can’t… We just can’t… We’re all gonna die…”  

Even if they had caught sight of it, a few A-rank heroes stood no chance against a monster that even top-tier S-rank heroes couldn’t defeat.  

The only result was more injuries and deaths.  

If those sacrifices had meaning—if they were necessary to hunt the monster—the heroes would’ve gladly thrown their lives away. But this? This was just meaningless slaughter.  

Even if heroes died fighting the Black Cat, Starlight still wouldn’t be able to catch it.  

Its stealth, its speed—everything was just too fast.  

The Black Cat understood humans too well.  

It knew exactly how to wear the heroes down, how to make humans afraid.  

The entire city had become its hunting ground, its playground.  

Has there ever been a monster that brought W-City’s heroes to such despair before?  

“Snap out of it! If S-rank heroes from other cities come to support, we can stop it! We just have to hold out until then!”  

“Sigh…”  

“We’re not even holding out right now… We’re just being dragged around, and so is Starlight.”  

No matter how much the A-rank hero tried to rally them, the others could only sigh in helplessness.  

Even if the heroes didn’t respond when the Black Cat appeared, the result would be the same.  

People would die, Starlight would chase, it would flee, and then instantly reappear in another district to kill more people like it was playing a game.  

Then, Starlight kicked open the door and stormed into the waiting room.  

“Hah… Hah… Hah…”  

“…You’ve worked hard.”  

Starlight, who had been racing back and forth across the city dozens of times, was breathing heavily—uncharacteristic for an S-rank hero.  

Without pause, Starlight immediately headed for the investigation room upon returning.  

Watching this, the other heroes let out sighs mixed with admiration and lament.  

“She’s amazing, really…”  

“She must be determined to catch it no matter what… The guilt must be eating her alive by now.”  

“Guilt? What guilt? The Black Cat’s just a fucking psycho.”  

“Damn it… If only Kage hadn’t pulled that stunt back then… If they’d just fought together—”  

“Everyone, to the investigation room!”  

“Yes!”  

The heroes, who had been muttering in exhaustion, immediately jumped to their feet and followed.  

Inside the dimly lit room, a large screen displayed every recorded sighting of the Black Cat so far.  

The heroes had been studying its abilities, trying to find a way to hunt the Despair-class monster.  

“That hole that appears when it throws its blade-tail… It looks like a wormhole.”  

“Maybe it’s an ability similar to its shadow teleportation.”  

“No, this is clearly spatial blinking.”  

“The blade-tail’s traces—victims say it’s ice hardened by its ability.”  

A whiteboard beside the screen was filled with notes on the Black Cat’s newly observed abilities and countermeasures.  

Except for one ability—shadow teleportation. There was still no way to counter it.  

“It disappears into the shadows and pops up on the other side of the city. There’s no way to react.”  

“This speed… It’s already beyond Despair-class. It might be close to Annihilation-class…”  

“Aaaah! We’re already running out of time, and now you’re saying we have less?! How are we supposed to stop it if it becomes Annihilation-class?!”  

“Will you shut the hell up?! Why are you freaking out now?!”  

“How can I not freak out?! There’s no way to stop that monster!”  

“You think you’re the only one with a headache?!”  

“Quiet! The ones suffering the most right now aren’t us—it’s the civilians!”  

Currently, W-City’s civilians have been trapped in shelters for three days straight.  

Unlike Disaster-class monsters, which S-rank heroes could definitively end, Despair-class monsters had no clear resolution. Hiding was the only way to minimize casualties.  

With the Black Cat appearing and disappearing at random to hunt humans, the civilians could only cower in fear, wondering if they’d be next.  

Their helplessness was even greater than the heroes’.  

“When will the S-rank reinforcements arrive?”  

“At best, two more days.”  

“Damn it… Thousands more will die by then…”  

“Enough! No more defeatist talk! Let’s focus on coming up with a plan!”  

“Is there even a plan to begin with…?”  

The A-rank heroes, drowning in despair, spoke in gloomy voices.  

Every plan so far had failed.  

When multiple A and B-rank heroes laid an ambush, the Black Cat just tore apart nearby shelters and mocked them.  

When they spread out to buy even a few seconds for Starlight, it only resulted in three more casualties.  

With nothing else to do, the heroes’ gazes naturally turned to Starlight—the only one who could even make the Black Cat flee.  

Starlight was staring blankly at the screen displaying the Black Cat’s appearances.  

“…This is weird.”  

Starlight—Yoo Anna—had been chasing the Black Cat nonstop, and something felt off.  

Three days ago, right after the Black Cat started hunting humans and fled in anger from a shelter…  

When reports came in that it had appeared in a completely different direction, Yoo Anna rushed there and threw a punch—but something felt wrong.  

That day, the Black Cat she faced was grinning excitedly, unlike the furious one from before.  

“It’s… Too different.”  

The first time, the Black Cat had scattered like mist from Yoo Anna’s punch.  

After landing a critical hit, it melted away like always.  

Then, it scattered like mist again…  

…Different.  

No, this is wrong.  

This is weak thinking.  

The Black Cat had simply dropped its thorough disguise and decided to start hunting.  

The game was over—all that remained was one-sided slaughter.  

As if to prove Starlight could no longer keep up, it was running rampant across the city.  

Monsters were like this by nature.  

When weak, they hid their instincts. When strong, they acted on them freely.  

But… Maybe.  

Yoo Anna felt uneasy, wondering if her thoughts were mistaken again, but she followed her intuition and moved her hand.  

“This… Is different.”  

Click, click. Yoo Anna pulled up every recorded video of the Black Cat from the past three days.  

As she began sorting through them, the other heroes’ eyes turned to her.  

Watching the multiple the Black Cats on screen, Yoo Anna’s eyelids trembled.  

“This one’s different… This one too…”  

“…Senior?”  

“Different!”  

What if—just maybe—  

Even as she dismissed the thought, Yoo Anna shot up from her seat and turned to the nearest A-rank hero.  

“Aside from the ice blades and spatial manipulation, were there any heroes harmed by its other abilities?”  

“Huh?”  

“Wait, no—the opposite. Lightning, fire, wind… Any heroes harmed by the Black Cat’s previously known abilities?”  

At her sudden question, the heroes glanced at each other.  

Not a single one raised their hand.  

Yoo Anna recalled how the Black Cat never retaliated against her attacks.  

Whenever it did counterattack, it only used new abilities—never the old ones.  

As the realization hit, her voice shook slightly.  

“Amorphous monsters change their form freely as needed. So why has the Black Cat maintained the same shape all this time? Because that form was advantageous? Because it was good for deceiving humans? No—because it looked cute…!”  

“Wait, what are you—”  

“It didn’t need to change its form! That appearance was already the perfect disguise!”  

Clatter! She shoved chairs aside and marched to the whiteboard, igniting flames at her fingertips to scorch words onto it.  

“Why… Why didn’t I think of this sooner?! Why?!”  

“What the hell are you talking about…?”  

Yoo Anna wrote Black Cat on the board and listed every observed ability:  

Stealth, shadows, swimming, lightning, flames, physicality, sound waves, shockwaves, telekinesis, regeneration.  

Then, in another section:  

“Code… A?”  

“Senior, what is that…?”  

Code A—a temporary designation for newly observed monsters.  

Below it, she wrote: stealth, ice blades, blinking, and other abilities before letting her hand drop weakly.  

“Y-You mean… This isn’t the Black Cat, but a different monster?”  

“Wait, then that insane speed…”  

“There’s not just one… We’ve been mistaken this whole time…?”  

“Why… Why didn’t we notice?!”  

“Noticing would’ve been the weird part…”  

The Black Cat was unique—a monster that could completely evade detection systems.  

For another monster to exist, one with the same appearance and similar abilities…  

It was so absurd that no one considered the possibility.  

That mistake had already cost 500 lives.  

As the heroes’ guilt peaked, Yoo Anna stared at the board and muttered, 

“…There might be one more.”  

“What?”  

She wrote Code B next to it, freezing every hero in the room.  

Then, she drew an = between A and B and clenched her fist.  

Two entities with identical abilities—like pack monsters, possibly a mated pair.  

“Otherwise, the movement speed and recovery don’t make sense.”  

“If the Black Cat had reached Annihilation-class…”  

“Annihilation-class wouldn’t need to hide! The Black Cat is still Despair-class!”  

“Wait, if that’s the case…”  

Currently, W-City has three Despair-class monsters: The Black Cat, Code A, and Code B.  

As despair deepened, Yoo Anna spoke in a trembling voice,

“If that’s true… Then…”  

A complicated emotion surged as a thought crossed her mind.  

With a whoosh, she summoned her ability, filling the room with scorching heat before slumping into a chair and holding her forehead.  

If her theory was correct… Should she be happy? Or sad?  

To confirm, she reviewed the footage again.  

“…Hah.”  

After scanning the videos, she made a sound somewhere between a laugh and a sob.  

“Were we… The ones getting in the way?”  

“Getting in the way…?”  

The meticulously organized footage showed the Black Cat exhibiting two distinct behaviors,  

One had its back to the shelters.  

The other was facing them.  

Yoo Anna’s head dropped limply.  

Bewilderment, absurdity—and then, a fleeting hope.  

This was insane.  

If she was wrong… This would be an even bigger blunder than Kage’s.  

But she had to do it.  

There was no other way to reduce casualties.  

With her resolve set, Yoo Anna looked around at the heroes and spoke.