Duo Leveling LITRPG | Post Apocalyptic | SYSTEM-Chapter 198 - 257 +258 - The Countermeasure

"It'll be fastest to start by understanding exactly what kind of enemy we're dealing with."

Michael pulled out his smartphone without preamble and showed a few photos. The first image was of the orb with the eye-like appearance—eerily familiar.

"We refer to this as the Phase One form. It might look like nothing special, but it's a monster capable of taking down level-300-class enemies all by itself."

Jhin's memory flashed briefly to when Cerberus and the one-eyed gargoyle had vanished without even putting up a struggle.

That was only Phase One.

"And this here is Phase Two."

This time, images of orb variants appeared—some like the one with wings in Kanubis, others in entirely different forms.

One had grown grotesquely large.

Another had split into dozens of miniature versions, swarming like a virus.

Clicking his tongue, Michael explained,

"From Phase Two onward, they undergo form changes. They evolve according to the strength of the opponent they're facing."

Because of that, they rarely reached Phase Two.

It required at least a level-400-tier threat to trigger that level of response.

"That's why I was so surprised. I didn't expect to see Phase Two come out against a freshly arrived player."

Jhin gave a bitter smile.

A Phase Two, evolving in response to him?

He couldn't wrap his head around it.

The vaccine evolved to fight level-400 monsters—and it did so against him?

Was it really just because of his fame as "Kyle"…?

"And this is Phase Three."

The image showed what was unmistakably a fully humanoid form. Jhin had seen it up close, even fought it—he hadn't forgotten its overwhelming presence.

"How powerful is that form?"

"It can take down a dragon on its own."

"…S-rank."

"Right. That's why we were lucky this time. Thanks to a surprise attack, we were able to take it down without much trouble."

But if they hadn't landed that surprise attack?

If that thing—capable of slaying dragons—had gone all-out?

Jhin felt a dull throb rise in his head.

And still, Michael went on.

"I've heard there's a level beyond that… though I've never seen it myself."

"Something above dragon-class?"

"Yes. This is Exodia 1, after all."

He wasn't wrong.

Dragons were strong, no question—but by the time the game was nearing its end, they were becoming increasinglyPowergeable.

Players had already started sharing strategies for clearing S-rank dungeons.

Michael gave a light shrug.

"As you've probably guessed, these things—we call them vaccines. They appeared to erase the 'residue' still crawling through a world whose service has already ended."

"…That's… pretty blunt."

"But not inaccurate. From their perspective, we're just leftover bugs."

Jhin nodded slowly.

Creatures that erased—no, deleted—everything they touched, now called vaccines?

Then yes… it wouldn't be strange to call those left behind bugs.

It was unpleasant. But it was real.

A world that had already ended…

To live on in such a place meant accepting that reality.

"But that's where we found a clue."

"…A clue?"

"Once we understood our situation—and accepted what they were—we started figuring out how to fight them."

Michael removed the magazine from his gun and held up a bullet. Up close, it was densely etched with something—lines of microtext, symbols, code.

"This… is the answer we discovered. The only weapon that can protect us. Can you guess what it is?"

Jhin squinted, inspecting the bullet closely.

If the enemy was a vaccine—and they were the bugs—then the countermeasure would be…

A dry laugh escaped him at the thought that came to mind.

"…A virus, right?"

"Exactly. More precisely—a self-replicating virus. It endlessly reproduces itself, overwhelming the system with runaway data."

"I see…"

Even a Phase One vaccine had staggered when flooded with sheer volume inside a lake.

While the orb hadn't been defeated after awakening into Phase Three, the lake strategy had still worked well enough to stall it during Phase Two.

A self-replicating virus would multiply infinitely, burdening the vaccine with a tidal wave of data. Literally the worst-case scenario for it.

To surpass a vaccine's deletion threshold using viral overload.

That's what players and NPCs in this sanctuary had discovered.

Their method of survival—as bugs living in a world trying to delete them.

"…That's a pretty elegant solution."

A virus—an all-too-fitting weapon for a post-service world.

Michael slid the magazine back into the weapon and said,

"We discovered it by accident. Turns out, Paradise is hiding more than we thought."

Paradise was something like the administrator's contingency.

A hidden village that didn't appear on any post-shutdown map. A place containing strange items capable of sealing memories.

This wasn't normal game design.

Just as Jhin had found a "backdoor" within Calamity Meteor, players and NPCs had stumbled across this place.

Here, they had developed weapons to fight the vaccines—refined strategies, designed systems, entered practical application.

"Truthfully, I'd rather let you try firing it yourself—get a feel for handling the virus in combat—but… now's not the best time."

"That's fine."

Michael gave a nod, but didn't move right away. Instead, he hesitated—then cautiously asked,

"…Could I ask something about New Capital?"

"What kind of news?"

"Ark. It's still intact… right?"

There was a nervous tremor in his voice.

Looking into those anxious eyes, Jhin slowly nodded.

It would be fine. Even if the moon was crashing down at this very moment—he believed they'd survive.

"It should be. There are still a few issues, but nothing the people there can't handle."

Lutz. Tempah. Bellatris. Millie…

Capable players. There was no way they'd fail to clear a second-run dungeon.

Even without him, they'd finish the job.

He had faith.

Michael placed a hand over his heart and exhaled.

"Thank god… haah…"

"…By the way, when did you end up here? From what I've heard, it seems like every player gets pulled in at a different time."

"I think it's best we first understand what kind of enemies we're facing."

Michael pulled out his smartphone and began showing a series of photos. The first image displayed the familiar orb-shaped creature with a pupil-like center.

"We refer to this one as the Phase One form. It may not look like much, but it's capable of taking down level-300 monsters on its own."

Jhin recalled the moment vividly—when the Cerberus and cyclopean gargoyle had been wiped out without resistance.

That had only been Phase One.

"And this is Phase Two."

Images flicked across the screen: the orb with wings that had emerged in Kanubis, along with other variants—some massive and bloated, others divided into dozens of smaller orbs.

Michael clicked his tongue.

"From Phase Two onward, they start to evolve—changing their form depending on their opponent's strength."

Which meant that under normal circumstances, they wouldn't even reach Phase Two. It took facing off against something at least level 400 to trigger it.

"That's why I was surprised. I didn't expect to see a Phase Two deployed against a newly transferred player."

Jhin gave a dry smile.

A monster that evolves to match a level 400 threat. Why had it taken that form against him?

Was it the notoriety of the name "Kyle"?

"And this," Michael said, "is Phase Three."

It looked fully humanoid. Jhin had seen it in person, even fought it, if only briefly—and he knew how terrifyingly strong it had been.

"How strong is that one?"

"It can kill a dragon on its own."

"…S-rank."

"Right. Which is why we were lucky this time. Thanks to the ambush, we were able to eliminate it without much resistance."

But what if they hadn't caught it off guard?

What if a creature capable of killing dragons had launched a proper assault?

Jhin could feel the pressure building in his temples.

And Michael wasn't done.

"There are said to be even higher stages of evolution… though I've never seen them myself."

"Something stronger than a dragon?"

"Yes. This is Exodia 1, after all."

It made sense.

Dragons—yes, they were powerful. But by the time the game was nearing service termination, people had figured out how to beat them.

Strategies for clearing S-rank dungeons were already widely known.

Michael shrugged.

"As you might've guessed, these things—we call them vaccines. They're here to delete the 'residue' of a world whose service has already ended."

"…Pretty blunt wording."

"It's accurate. From their perspective, we're nothing but bugs."

Jhin nodded silently. 𝙛𝒓𝒆𝙚𝒘𝒆𝓫𝙣𝓸𝙫𝓮𝒍.𝒄𝒐𝓶

They didn't just destroy; they erased. If they were vaccines, then players and NPCs like him—still lingering after shutdown—were bugs.

It was a grim reality. But real.

Surviving in a world after its end… meant accepting truths like this.

"But that's where we found our clue."

"A clue?"

"When we accepted our status—and acknowledged what they were—we finally began to understand how to fight them."

Michael removed the magazine from his gun and pulled out a bullet.

At first glance, it looked ordinary—but upon closer inspection, the casing was densely covered with strange characters and patterns.

"This is the answer we discovered—the only weapon that can protect us. Can you guess what it is?"

Jhin narrowed his eyes, studying the bullet.

If the enemy was a vaccine and they were the bugs, then the answer had to be…

A quiet, dry laugh escaped his lips.

"…A virus, huh?"

"Exactly. More specifically—a self-replicating virus. It continuously replicates itself and forces a data overload."

"I see…"

The orb-shaped Phase One vaccine had lagged when it tried to erase an entire lake's worth of data.

The lake tactic hadn't been able to kill it once it evolved into Phase Three, but during Phase Two, it had worked.

A self-replicating virus would flood it with infinite data. For a vaccine, it would be a critical vulnerability.

To exceed a vaccine's deletion limit with overwhelming data—that was the countermeasure discovered by the remaining players and NPCs in Paradise.

"…Fascinating."

What could be more fitting for a post-service world than a virus?

Michael slid the magazine back into his gun.

"It was a technique we discovered by chance. Paradise is hiding more than we ever expected."

Paradise—a settlement not listed on any map. Capable of sealing memories. A place likely left behind by the administrator.

It wasn't part of the game's original system.

Just as Jhin had discovered the "backdoor" within Calamity Meteor, the survivors had discovered this place.

Here, they had found a way to fight vaccines—developed it, refined it, and turned it into a viable countermeasure.

"Of course, it'd be best for you to learn by firing the gun yourself and getting used to handling viruses… though that may be a bit difficult right now."

"That's fine."

Michael looked slightly apologetic, then hesitated for a moment before asking,

"…Could I ask you something about New Capital?"

"Sure. What about it?"

"Ark. It's still standing… right?"

Jhin caught the unspoken anxiety in his voice. He met the man's eyes and slowly nodded.

"It's intact. A few minor issues remain, but nothing they can't handle."

Lutz,Tempah, Bellatris, Millie…

They wouldn't fail. Not on a second-run dungeon.

Even without him, they'd get through it.

He believed in them.

Michael placed a hand over his chest and let out a long breath.

"…That's a relief. Truly…"

"By the way," Jhin added, "when exactly did you end up here? I heard players get transferred at different times."

Michael nodded.

"I think it was about two weeks after Bey World was deleted."

He had been investigating the remnants of Bey World when he suddenly fell into an unidentified wormhole.

That was why he had joked about the "Platform Nine and Three-Quarters."

"…That must've been rough."

"Yeah. It really was."

Their conversation continued for a while after that.

Michael mixed in his personal experiences and spoke for quite some time. It was only when the moon began to fade and the first morning light crept through the window that he finally returned to his lodging.