Chapter 15
Being able to bring weapons into the venue so easily… when I think about it calmly, that explorer’s must-have item—the “four-dimensional whatchamacallit,” the Dimension Space—might actually be a dangerous invention.
As I pulled my beloved sword from my leg pouch, that thought briefly crossed my mind.
“Got a plan, Onee-san?”
“Lately I’ve been fighting with magic only, so maybe this time I’ll hang back as rear support?”
“Roger. They’ll probably all come pouring out of the dungeon at once, so knock down the front line. That should sap the momentum of the ones behind them too—then I’ll crush them in one go.”
“Mmm, figures—fighting alongside me for so long has really built up your experience, huh, Akira? It’s been a while since we fought together, so your big sister’s going to get a little fired up!”
I raised my sword and sprinted toward the huge hole that had just been born.
The hole seemed to be shaped like a slope, forming a path that spiraled up from inside the dungeon to the surface, almost like a helical passage.
Floodlights revealed a massive horde of monsters writhing, as if about to fill that spiral completely.
“There’s no way we can collapse the dungeon, right? I mean, obviously.”
“It’s not something you can crush physically. Even if you dropped a missile and destroyed the entrance, the entrance would just remain inside the crater. Once a dungeon is born… you can’t destroy it from the outside.”
Then there was nothing to do but fight.
The monsters finally reached the surface and set foot on the grassy plain of the reclaimed land.
Like rush hour at a major city station, an overwhelming number of monsters came pouring out in a torrent.
But—
“Front row, take a tumble!”
At my sister’s shout, the monsters in the front line all fell to the ground at once.
Their legs had suddenly been “sewn together”—to the ground, to their other legs, to the legs of neighboring monsters.
At first glance, her magic always seemed plain.
Magic to manipulate hemp rope.
Magic to grow branches.
Magic to fire old nails.
Magic to create burning charcoal.
All of it mundane, with no unity or consistency—magic that could only control what looked like junk.
But I knew. I had seen her use this magic with absurdly precise control, instantly suppressing enemies, pinning them in place, and refining it into killing blows.
And right now, with their legs entangled in hemp rope, the front ranks of the horde were halted in an instant, crushed by the monsters behind them, their formation thrown into chaos almost immediately.
“Akira, push forward as far as you can at full power! This is a great chance to gain experience fighting a huge mob!”
“Roger. …I’m going all out.”
My weapon is agility. And speed is, in other words… destructive power.
Originally, strength and agility should be equivalent stats. But my raw attack power is low.
That’s why my sister once taught me a way to convert speed into attack power.
She made me polish the technique—how to efficiently carry speed into an attack, how to transmit force cleanly into a blow.
“…Now I get it. The instant my power reaches the very tip of the blade, I understand the essence of attacking.”
During summer vacation, I landed countless blows on living humans without weapons.
How to transmit power efficiently.
How to strike like my sister—a master who knows all of humanity’s accumulated knowledge.
All the trial and error, all the training, every time I unleashed a technique—everything was etched into me at [Experience Gained ×10].
I kicked off the ground and surged forward. In an instant, I was right in front of the disordered monster horde.
Holding the sword in a reversed grip, I swung as I ran through them.
The monsters I touched were sliced apart like soft jelly, bursting and flying off, offering no resistance as I cut my way forward.
My speed never faltered. Cutting them down, slicing them apart, blasting them aside, sending them flying—I ran in a frenzy, swinging my sword again and again.
I even stepped into the dungeon itself, pressing on as far as I could while continuing to cut down monsters.
Eventually, the sword could no longer carve through their bodies, and my attack stopped.
In that instant, I leapt, landed atop the monsters, and ran across the horde to return to the surface.
“Eighty-seven kills. Even after cutting down that many, it hardly feels like they’ve thinned out.”
“Whew! I’ll give that attack eighty points! You cut too deep into enemy territory. Partway through, you should’ve changed direction and cut along a trajectory that split the horde in two.”
I gave a wry smile at the strict assessment from my partner—and mentor.
Honestly, that attack had felt really good. Even so, I hadn’t been able to kill the horde’s momentum. I’d reduced their numbers, but that was all.
“Akira, you’ve gained experience. You’re starting to understand how to load destructive power into your sword, right? Then it’s time for the next stage—use your fist techniques with a blade. At your level now, you should be able to generate blade pressure just through the sharpness of your technique.”
“Huh, seriously? I can do something that game-like?”
“What are you talking about? You were already moving like a game technique just now. I thought it was cool—like one of those stylish action games from Cap○om.”
“Seriously? …Okay, I’ll trust you, Sis.”
“Good. Listen carefully. Fajin is about concentrating all your destructive power into a single point and delivering it directly to the enemy in an instant, without waste. If you can reproduce that with a sword, the destructive force will dwell in the blade. A sharp force becomes a strike that cuts through the air itself. Akira, trust your speed. The speed at which you swing the sword is speed all the same.”
I understood the theory. She was certain I could do it. She must have given me the techniques and training for this moment all along.
Then all I could do was believe—and strike.
I could see it: our attacks were starting to rattle the monster horde, just a little.
I could tell they were hesitating, reluctant to press their advance.
“…Hah!”
I swung the sword with everything I had.
The force from my stepping foot, the power flowing through my arms—every bit of it was transferred cleanly into the blade, without waste.
The sword flashed through empty space in an instant, yet I felt a sensation as if I had cut something.
“Just now… I think something came out.”
“Woo! Pulling it off in one try—nicely done, Akira. Go on, take a look.”
At the very front of the horde, the monsters had frozen.
Then, in the next moment, their bodies—shifted.
A group of monsters, sliced at the same diagonal angle as my sword swing, slowly slid apart.
Like a tilted daruma-doll stacking game, their bodies drifted, collapsed, and fell away.
“W-What… was that? Some kind of wind blade…?”
“It’s blade pressure—sword aura, you could say. Normally it’s a technique humans can’t use. But… this world is gradually integrating magic as a natural phenomenon. The groundwork has been laid for techniques and phenomena that used to be impossible to become possible. You stepped into that realm on your own, Akira—into territory that’s usually reproduced with a [Skill].”
I’d just unleashed an attack that normally only becomes usable through a [Skill]… on my own?
I knew of one like that. A pretty top-tier skill, classified as a real “hit”: [Sword Flash].
From what I knew, it added a shockwave to a powerful sword strike, and when fully mastered, you could fire it outright. And I’d just reproduced that by myself… That’s amazing! Seriously amazing!
“Sis, I think I can fire that last attack more efficiently next time.”
“Of course you can. [Experience Gained ×10] is downright cheating. And [Enhanced Body Perception], too. Because of that, once Akira uses an attack even once, his body memorizes it completely.”
“It really puts a lot of strain on my arms, though—more than when I hit something directly.”
“Naturally. You’re swinging at full power with no resistance. Your body itself can’t quite keep up with your speed yet. You’ll need to level up and work on conditioning your body too. Eat your protein, okay?”
Even as we cut them down, the enemies kept spawning one after another.
Honestly, it should have been a difficult situation for just the two of us to hold back—but as long as she stayed her usual self, I couldn’t help feeling like we’d be fine.
“By feel, I’ve got maybe three more shots like that. My shoulders and arms are about to give out.”
“Alright, then I’ll step forward a bit too. Let’s hang in there a little longer until reinforcements arrive.”
Right—other explorers should be converging on this place as well.
So… there was no room for whining.
More than anything, this situation was delicious.
It was a chance to grind experience, even though I wasn’t supposed to be able to enter dungeons yet.
“…I’ll hunt, and hunt, and hunt some more.”
“Alright! Big sis is about to unleash her ultimate Maid Punch!”
If we could just endure like this, then that meant victory… right?
Feeling the tremors from the ground growing stronger, we charged once more into the enemy horde—