The first thing I tried was binding it with puppet threads.

Naturally, it didn’t work. The blade-like edges at the tips of its tentacles easily sliced through the slowly extending threads.

"Figures…”

I had wondered if it might ignore them since they were something trivial, but no.

Letting out a sigh, I slowly backed away while watching it.

'Let’s just observe what kind of thing this is first.'

Just from the increased pressure around it, it was clear that this wasn’t an ordinary deep-sea creature anymore.

And indeed, it didn’t try to attack me with its tentacles.

[...]

As if calculating something, it stared at me with its countless eyes, acting as though it didn’t care whether I retreated or not.

Did it judge me as a threat? Or was it aiming for something else?

There was no way it would just let me go, so I waited, ready to respond if it made the first move, but—

"...Huh?"

The tentacles suddenly crumbled.

They literally turned to dust and vanished. All that remained was the ragged body of Fishman floating there.

Startled by the sudden self-destruction, I quickly wrapped myself in a pressure barrier and approached its body.

Whatever happened, this was an opportunity. If I could bind the main body with threads, it would be over without even needing to fight.

At that exact moment.

-Crunch!

"Kgh-!"

A crushing impact spread through my body, like my organs had been pulverized.

Through my blurring vision, I looked down at my grotesquely caved-in abdomen as I collapsed.

It felt like being struck head-on by a massive iron club. My pressure barrier had provided no protection at all.

I barely swallowed the blood rising in my throat and focused my Tide Sense, scanning the surroundings.

At first, I saw nothing. But when I pushed further, enduring a greater burden—

I sensed a different kind of flow within the Abyssal Sea.

"Tsk..."

Steadying myself, I focused on it, and only then did the tentacles become visible again.

They had changed form. From organic matter into the water of the Abyssal Sea itself.

I could pull the same kind of trick. I manipulated the currents and pressure, manifesting invisible tentacles of seawater similar in size.

'What the hell?’

Clutching my stomach, I stared at the construct I had created, feeling quite puzzled. The immense precision and accuracy were so beyond what I should be capable of that I could hardly believe that it was my creation.

Even compared to before entering this Abyssal Sea. It was on an entirely different level.

...At last, I was starting to get a sense of what had changed during this dive and why so many things felt different.

But now wasn’t the time to think about that.

[Oh, oh, oh, oh…oh……!!!!!!]

Fishman’s main body let out a grotesque noise and pointed at me with its shriveled fingers.

What it was commanding was obvious. I immediately extended the tentacles I had created, trying to block them.

It was a futile attempt.

-Srrk…

"What the…?!”

Fishman’s tentacles passed straight through the ones I had formed with currents as if they didn’t exist at all.

Startled, I shoved the water forward with all my strength and retreated, barely avoiding the incoming strike.

It wasn’t a perfect dodge. The tentacles pierced even my protective layer and left a shallow cut on my cheek.

I wiped away the blood with my sleeve before it could spread in the sea, clenching my teeth.

"...Is it even fair to do something like this?”

If they just transformed into seawater, I could’ve done something similar.

But it wasn’t like that. Those seawater tentacles weren’t affected by pressure or currents at all.

After a moment of thought, I understood.

'It’s not seawater I can control.'

The seawater I manipulated and the seawater that thing had become were fundamentally different.

If I had to put it into words, it was using a kind of water that only it could control within this Abyssal Sea…

And I couldn’t.

The moment I realized that, a deep sigh escaped me.

'Then what the hell am I supposed to do?'

In this Abyssal Sea, neither pressure nor currents worked.

In other words, it was close to invincible in this place. It alone was able to ignore the rules.

Before I could think of a solution, Fishman snapped its neck again and raised a finger.

[A-aaaah...!!]

A primal scream, like something a tortured human might produce without ever having learned how to speak.

The sound alone was enough to make my skin crawl.

There was no method to counter it. I tried to create distance first, but—

"Kgh."

Distance didn’t seem to matter to those tentacles.

In an instant, they surrounded me and began crushing inward. Dodging had its limits, so this time I used magic to try cutting them.

Stars flashed in my eyes as blades of wind, formed from mana, sliced through the tentacles.

It worked. The tentacles were clearly cut in half.

But they were, in the end, just seawater.

In other words, they consisted of water.

"Ugh…!”

The severed sections rejoined instantly.

Still, I noticed a tiny gap of about 0.1 seconds. The moment they tightened around me, I lashed out wildly at the surroundings and barely escaped, though pain surged through me as if my bones had been broken.

If this weren’t the Abyssal Sea, where I could still move freely using the currents, I would’ve been immobilized and finished already.

Realizing that even magic had little effect, I changed my approach.

'I’ll just run.'

At least for now, I had no way to deal with that thing.

Of course, it didn’t look like it would let me go easily now that it was fully engaged, so I resorted to a more extreme method.

"Sorry, we'll continue this later. Not right now.”

I tore off the sleeve I had used to wipe my blood earlier and threw it outside my Water Partition.

My blood spread through the currents, dyeing the deep sea with a horrific scent so intense that even I struggled to keep my sanity.

Soon, thousands of deep-sea creatures would come rushing in. I planned to escape in that chaos.

But…

"...Huh?"

1 second.

3 seconds.

10 seconds.

Even after nearly 30 seconds passed, there was no reaction.

That made no sense. Confused, I expanded my Tide Sense, which had been focused only on the tentacles up to that point.

And then—

"What...?"

I saw a hellscape.

The Abyssal Sea was always hell, but this was far worse.

The creatures followed their instinct. The moment they smelled the blood, they swam toward me in a frenzy, trying to kill me.

But at the same time—they were being destroyed.

-Crack, crunch…Pop!

"...Hah."

Wrapped in something invisible, pierced, and eaten. They would simply die the moment they entered a certain range, not a single one getting through. 𝑓𝑟ℯ𝘦𝓌𝘦𝘣𝑛𝑜𝓋𝑒𝓁.𝑐ℴ𝓂

The sea was painted in a multitude of blood. The scent brushing my nose was overwhelmed by even more horrific pheromones.

Death, death, death, danger, danger, danger.

If I were a deep-sea creature, I would never approach this place. Before long, the area became a sterile zone, completely free of any creature.

I let out a hollow laugh.

So this was how deep-sea fish dealt with it. Well, if pressure and currents didn’t work on it, something like this made sense as an alternative.

The tentacles that had slaughtered everything slowly turned toward me.

As I snapped back to reality, another voice spoke up.

[...Ugh, why does it feel like my flesh is being cut…?]

It was Malo, my robe.

It must have woken up from being soaked in my blood and torn apart.

I gathered as much mana as I could, preparing to struggle, and greeted it coldly.

"Why don’t you go back to sleep? I don’t think staying awake will end well for you.”

[What are you talking about…? Wait, what is that?]

"Hard to believe, but that’s the thing trying to kill me right now.”

Malo looked at Fishman in confusion.

Since it couldn’t perceive the Abyssal Sea, it only saw what looked like a corpse. It couldn’t possibly understand the situation.

But surprisingly, it reacted with shock, tightening around me.

[Wait—I-is that a Sealed System? I’d only heard of it in theory! To think something like that actually exists…]

"A Sealed System?"

At the unfamiliar term, I titled my head. Malo continued in a panicked tone.

[It’s a world within a world, created when countless beings possessing the same kind of world gather and become one. The creator spoke of it occasionally. But for such a thing to exist, identical worlds must exist, and since each world is supposed to be unique, it was considered impossible... And yet, that thing is a perfect unification of countless worlds. Truly incredible, truly…]

"I have no idea what you’re talking about.”

Frowning, I suddenly caught onto something and quickly asked,

"So, does this ‘Sealed System’ or whatever have a weakness?”

[A-a weakness?]

"Yeah. Because if it doesn’t, I think I’m going to die here.”

[I-I see! You’re actually fighting a Sealed System…then just run. Right now, you’re not fighting an individual, but engaging in close combat with countless worlds. In that situation, running is the correct choice.]

"I’d love to do that, but it doesn’t seem like it wants to let me go."

[Tsk, this is so troublesome. A weakness, a weakness…]

After thinking hard, Malo spoke in a low voice.

[P-perhaps opening it would work.]

"Opening it? What?”

[A Sealed System is, in the end, countless worlds acting with the same will. If another world enters it, it will immediately collapse. If you could open their world and contaminate it…]

"How do I open it?”

[I don’t know. This is the first time seeing a Sealed System as well.]

Intrusion. Contamination…

Countless possibilities flashed through my mind and vanished as the tentacles drew closer—

And then, one possibility surfaced.

"...Alright."

I had nothing to lose.

I thought about the fall of the Empire.

...It was unfortunate, but it didn’t stir much anger within me. My sense of patriotism had long since faded.

[J-Jern, that thing looks like it’s about to do something…]

Staring at the approaching tentacles, I then thought about my own death.

A life in which I fell into the Abyssal Sea due to some stroke of bad luck. And here I was, about to die because of the same thing.

Only then did my heart ignite with anger.

A colder anger than anything else.

"—So this is what it feels like."

I murmured with a slow smile.

"Let’s see what you really look like…”

And in the next moment—the tentacles that were barely visible even to my Tide Sense became visible to my eyes.

It was frozen completely solid, taking on a pure white color.