Deep within the mountain ranges surrounding the River Country stood a hidden underground facility.
Rows of figures in black robes moved in silence. Around each of their necks hung a silver pendant shaped like a circle enclosing a downward-pointing triangle. Their presence alone weighed heavy on the air.
"Shinji Akagi. Hidan. Once blood extraction is complete, proceed to hand-to-hand combat training."
"Yes, Lord Takigawa."
In a broad chamber lit by rows of burning torches, two silhouettes collided again and again.
Fist met flesh.
Knee slammed into ribs.
Elbows, kicks, headbutts.
The sounds never stopped.
One boy was thrown to the ground.
He rolled.
He surged back up.
Then the other fell.
Again.
Again.
Again.
The fight quickly abandoned anything resembling technique. No clean forms. No structured exchanges.
Only endurance.
Only will.
Punch for punch.
Kick for kick.
Whoever collapsed first lost.
There was nothing elegant about it.
Nothing impressive.
Two teenagers, fourteen or fifteen at most, beating each other like animals.
Their martial skill was mediocre at best.
But their bodies told a different story.
Strength far beyond their age.
Bones that refused to break.
Muscles that kept moving long after exhaustion should have taken over.
The robed observers continued writing notes.
This was not training.
It was data collection.
"Enough."
A calm voice cut through the chamber.
A middle-aged man stepped forward. Unlike the others, he wore a dark crimson robe. His face carried a gentle smile, warm and approachable. The kind of man who looked like he might offer candy to neighborhood children.
This man was Lord Takigawa.
Founder of the Jashin Cult.
A man whose doctrine was simple.
Endless slaughter.
Under his guidance, the cult had quietly expanded through the River Country and beyond, leaving mass disappearances in its wake.
Their name had become taboo.
The two boys froze mid-strike.
Their fists hovered inches from each other's faces.
"Tch. You're lucky," said the silver-haired boy with slicked-back hair and magenta eyes. A damaged forehead protector hung loosely around his neck. "Another second and your skull would've popped."
He looked anything but threatening.
Purple bruises.
Swollen cheek.
Mud and dust smeared across his clothes.
The other boy withdrew his fist.
Same height.
Short brown hair.
Pale skin.
Sharp eyes.
A fragile-looking face that lied beautifully.
Because moments ago, he'd been fighting like someone who didn't care whether he lived or died.
Shinji Akagi tilted his head slightly.
"Those honey-soaked pillow fists of yours?" he said calmly. "If your goal was to sweeten my mood, congratulations. You succeeded, Hidan."
"AKAGI SHINJI!"
Hidan's killing intent exploded outward.
"Blasphemer! I'll carve you apart!"
Shinji stepped closer, pressing his forehead into Hidan's chest.
"You know, I take it back."
Another shove.
"At least you don't cry for your mommy when you're getting beaten."
Shove.
Shove.
Hidan's eyes went bloodshot.
That was it.
"Screw it!"
He yanked a black spear from inside his robe and drove it forward.
Straight through Shinji's chest.
SPLURT.
Pain detonated.
White-hot.
Explosive.
Even after dying countless times, having his heart pierced never became easier.
At the same moment—
Shinji thrust upward.
A combat knife buried itself fully into Hidan's throat.
No hesitation.
No mercy.
Both had chosen mutual destruction.
They collapsed.
One with a hole through his heart.
One with a crushed windpipe.
The cultists did not move.
They did not react.
They did not intervene.
Three seconds passed.
Hidan's hand twitched.
He grabbed the knife lodged in his neck and yanked it out.
Blood sprayed.
He gagged.
Coughed.
Staggered upright.
The wound began knitting itself together.
Across the room, Shinji's eyes snapped open.
He sat up, grabbed the spear from his chest, pulled it free, and tossed it aside.
His heart regenerated.
Because this world had dragged him here without consent.
So he adapted.
If survival required killing, he would kill.
If survival required dying, he would die.
He spat blood onto the floor.
"That was it?" Shinji said. "My grandmother hit harder than that."
Hidan ground his teeth.
They both knew the truth.
They were survivors of the same ritual.
The ritual that granted pseudo-immortality through a cursed binding.
A blessing from Jashin.
Hidan had killed Shinji many times.
Shinji had returned the favor just as often.
Sometimes they died together.
Sometimes Shinji killed him first.
Once, Shinji had decapitated Hidan and buried the head separately.
The cult spent three days searching before Lord Takigawa forced Shinji to reveal the location.
Since then, everyone understood one thing.
Shinji Akagi was not weak.
He was dangerous.
Which was why Hidan usually limited himself to trash talk.
Because killing Shinji never stayed a win.
"Playtime's over," Lord Takigawa said pleasantly. "Your stamina remains excessive. Rest period canceled. Proceed to Chamber Two. The materials are ready."
Hidan snorted and walked away.
Shinji followed.
Neither looked back.