Only Getting Hit Is Unfair
The Bulssiseok was no ordinary fire-spitting rock.
It was a mineral that converted the surrounding mana into heat.
With enough mana, it could burn for days on end.
Without mana, it was little more than a warm hand warmer.
I placed the Bulssiseok inside the old gas furnace.
“Ihyeon, are you sure this is okay?”
Grandpa asked, fire extinguisher already in hand.
“Yeah.”
“From where Grandpa’s standing, it doesn’t look okay at all.”
Three fire extinguishers sat around the furnace.
One would have been enough.
Apparently three were required for peace of mind.
“You shut off the gas, right?”
“Checked it twice.”
“And turned on the exhaust fan?”
“Yeah.”
“Our Ihyeon is not allowed to step past that line over there.”
Grandpa pointed to the yellow line he’d drawn on the floor.
It was a full five paces from the furnace.
In my past life’s forge, that distance would have gotten me thrown out before the fire was even lit.
But a promise was a promise.
I stood obediently behind the line.
“Start it.”
Grandpa flipped the switch beside the furnace.
A copper plate the size of the back of a hand lit up.
It was the same mana-collection circuit I’d used for the Strength Assist Gloves.
Ambient mana flowed along the copper wires into the Bulssiseok.
The light inside the red stone quickened.
Thump.
Thump.
Then a blue flame bloomed.
Whoosh!
“Ihyeon!”
Grandpa raised the extinguisher.
“It’s normal!”
“The fire’s blue?”
“That’s why it’s normal!”
Grandpa kept his grip on the safety pin for a long while.
The flames never spilled outside the furnace.
They spun in a neat circle along the firebricks inside.
In my past life, a master judged temperature by the color of the metal.
This time I had inserted a thermocouple.
Numbers climbed on the small screen beside the furnace.
Eight hundred degrees.
One thousand.
Twelve hundred.
At the temperature I wanted, the collection circuit shut off automatically.
The flames subsided.
“Done.”
Constant temperature.
Automatic cutoff.
A fire even I—who couldn’t use mana—could handle.
It was smaller and weaker than the forges of my past life.
But far easier to control.
This was the first furnace that combined modern measuring equipment with the mana circuits of my previous life.
Grandpa looked back and forth between the screen and the blue fire.
“Can we turn it off now?”
“We haven’t even put anything in yet.”
“Grandpa feels like he’s already seen enough.”
We hadn’t even started.
Disassembling Choi Minseok’s shield alone took half a day.
Once the outer plates came off, the crushed shock absorbers were exposed.
Spiderweb cracks spread across the inner steel plate.
“This one’s beyond straightening,” Grandpa said.
“Yeah. The center has to be cut out.”
“And we just weld on a new plate?”
“If that’s all we do, it’ll just crumple the same way again.”
The original shield was built to take frontal impact with thick steel alone.
If the plate held, the shield was fine.
Whether the arm of the person absorbing that force stayed fine was never considered.
Equipment exists to protect its user.
If only the gear survives while the user doesn’t, it has no meaning.
I sketched a new frame on the inside of the shield.
Four metal joints radiated from the center out to the edges.
It was similar to a car’s suspension.
When impact hit, the joints would fold a little.
The remaining force would be channeled out to the rim.
“Let’s put springs in here.”
“We don’t have springs at the ironworks that can take that kind of force.”
“Then we make them.”
Easy to say.
Actually making them took ten days.
On weekdays I could only come to the ironworks after school.
And even then I had to finish my homework before I was allowed near the workbench.
“Finished the multiplication tables?”
“Finished.”
“Dictation practice?”
“Did that too.”
“And the homework notebook?”
“……I’ll go get it.”
In my past life I had ignored even a king’s orders to pick up a hammer.
Now I needed a confirmation stamp in my homework notebook before I could pick one up.
Reincarnation really did come with a lot of inconveniences.
The first metal for the furnace was decided.
We cut an old leaf spring into four thin rods.
Grandpa used tongs to place the metal into the furnace.
Blue flames wrapped around the steel.
It heated evenly, the red glow rising at a steady rate.
Unlike a gas torch, one side never cooked first.
“Pull it now.”
Grandpa laid the glowing steel on the anvil.
I put on the Strength Assist Gloves.
Lowered the face shield and took up the hammer.
Clang!
The first strike rang through the ironworks.
Last time I had restored the shape of a broken sword.
This time I was giving form to metal that had none.
Clang!
With every blow the leaf spring stretched thinner and longer.
All four pieces needed the same length and the same curve.
If even one differed, the impact would concentrate on one side.
I struck only the center of the glowing metal.
Grandpa flipped the steel before I even spoke.
“Need to stretch this side a little more, right?”
“Yeah. You’re getting good at this.”
“I’ve been watching our Ihyeon the whole time.”
There was a touch of pride in Grandpa’s voice.
Our rhythm was perfect.
Even with the apprentices of my past life, reaching this level had taken years.
The snacks had been worth it.
After the four metal joints were finished, we assembled them first on a test wooden board.
Grandpa pulled back the sandbag hanging from the ceiling.
“Letting go.”
“Okay.”
The sandbag slammed into the center of the board.
Thud!
The metal joints folded and bled off the force.
The three on the right moved properly.
The upper-left one lagged by half a beat.
The board twisted hard to the side.
In a real fight, Minseok’s shoulder would have gone with the shield.
“We made them together—why is only this one different?”
Grandpa detached the joint.
Thickness was the same.
Length was the same.
The problem was heat.
It was the piece we had put in before the furnace temperature had fully stabilized on the first run.
A difference too small for the eye to see had changed the elasticity.
“We’ll remake this one.”
“Right. Can’t have our Ihyeon’s shoulder going out of joint.”
It wasn’t my shoulder, but I didn’t bother correcting him.
I drew a red line on the failed joint and set it aside.
I didn’t throw it away.
Material whose failure you understand becomes a tool that prevents the next failure.
Once the metal frame was complete, I engraved the mana circuits.
The circuits branched from the center of the shield in four directions.
A dispersion circuit that sent impact out to the edges.
That alone would have been enough.
But something still felt lacking.
I stared at the empty space left in the center of the shield.
Did the force really have to just be bled off and end there?
Mana was power.
If I could store a portion of the force every time a monster struck the shield…
“Give me one more Bulssiseok.”
“I said we were keeping the last two as furnace spares.”
“I’m putting it in the shield.”
Grandpa’s expression turned uneasy again.
“This isn’t going to explode, is it?”
“It won’t.”
“You also said the blue fire was normal a little while ago.”
“And it was normal.”
That wasn’t wrong.
I sealed the Bulssiseok inside a thin metal box.
I cut the heat-generating circuit and connected only an accumulation circuit that would store force.
Every time the shield took a hit, a portion of the impact would build up in the Bulssiseok.
The stored force would release through the front of the shield when the trigger on the grip was pulled.
A structure that returned the blocked force exactly as received.
Putting a counterattack function into armor had been rare even in my past life.
Because the craftsmen who made shields and the ones who made magical tools were separate people.
I could do both.
With modern engineering added on top, there was no reason to choose only one.
Finally I ground the iron-armored boar’s horn thin and layered it across the front of the shield.
The black horn stretched in four branches from the center to the edges.
It looked like decoration, but its real job was to transmit impact into the frame.
The finished shield was a little smaller than the original.
The weight had dropped by nearly three kilograms.
In exchange, a double-layered metal frame and mana circuits filled the interior.
I stood the shield up and tapped it lightly with a finger.
Ting.
A clear note rang out.
For the final test we used a sandbag twice as heavy as before.
Grandpa fixed the completed shield to the test stand.
The sandbag slammed into the center.
Boom!
The shield slid backward.
But it did not twist.
All four metal joints folded at once and bled the force out to the edges.
A single line of red light filled the Bulssiseok in the center of the shield.
The impact had been stored properly.
I pulled the trigger beside the grip.
Thump!
The front of the shield shuddered.
The sandbag that had been stuck to it flew off in the opposite direction.
Grandpa watched the sandbag sail away.
“So the shield hits back too.”
“It’s unfair if you only get hit.”
Return exactly as much as you were attacked with.
A fair shield.
“It’s finished.”
This time it wasn’t a repair.
I had only used materials from the broken shield.
The structure.
The circuits.
The functions—everything was newly made.
The first custom piece of equipment I had created in this world.
When we called him, Choi Minseok came with Park Doyun.
As always, a strawberry milk was in Doyun’s hand.
“For Ihyeon.”
“Thank you.”
By now even the motion of poking the straw in felt familiar.
Minseok couldn’t take his eyes off the shield on the workbench.
“Is this really my shield?”
“About half of the original shield is still in there,” Grandpa answered.
Half.
More than I had expected to leave.
Minseok slid his arm through the grip.
“It’s light.”
When he moved his arm, the metal joints shifted minutely to match his stance.
The shield never left his body.
“The grip feels good too.”
“That’s not all.”
I said.
A system window seemed to have appeared in front of Minseok’s eyes.
His gaze flicked rapidly left and right.
“C-class?”
Doyun immediately crowded in beside him.
“What’s it say?”
Minseok slowly read the contents aloud.
Grade: C
A shield combining modern shock-absorption structure with mana circuits.
◈ Impact Dispersion: 41%
◈ Stores a portion of received impact.
◈ Stored impact can be released upon shield bash.
The ironworks went quiet.
Doyun spoke first.
“Boss.”
“Yes.”
“Do you make shields from scratch as well?”
Instead of answering, Grandpa looked at me.
I took a sip of strawberry milk.
“We should test that first.”
Minseok looked down at the shield.
“How do we test it?”
“Wouldn’t getting hit by a monster work?”
Minseok’s face stiffened.
A shield was made to be hit.
I couldn’t understand why he was making that face.