The desert roared around them.
The sun had long begun its descent, casting a deep orange glow across the dunes as Rex led Luffy and Usopp down the hidden eighth path — the buried caravan trail, lost to time and storms. Sand slid beneath their feet as they crossed the bone-dry ravine, walking between cliff faces carved by forgotten winds.
"Man, this place is creepy…" Usopp muttered, looking around with wide eyes. "It's too quiet. Like even the sand wants to eat us."
"We're almost through," Rex said, eyes scanning ahead. "Crocodile thinks he's five steps ahead, but we're already behind him."
Luffy adjusted his straw hat. "Then let's make it zero."
Usopp laughed nervously. "Let's not forget about me in the dust storm, yeah?"
They pressed on — unaware that the trail beneath them was thinning.
A vibration tickled Rex's boots.
Crunch.
The ground cracked.
His eyes narrowed.
"Jump—!"
CRACK—!!
The earth collapsed beneath them.
The trio dropped, shouting as they were swallowed by a sinkhole wrapped in swirling sand and stale air. They crashed down hard into darkness — not soft desert, but stone.
Underground Chamber – Lost Shrine Beneath the Desert
A low, cold silence filled the room.
Carved stone stretched in all directions, lit faintly by ancient fire crystals embedded in the walls. Symbols none of them recognized spiraled along the pillars. Dust fell from the ceiling like snow.
"Wh-Where the heck are we?" Usopp coughed, brushing off dirt.
Rex stood slowly, examining the air. It was… strange. Heavy. Something else had awakened when they landed here.
[…Warning: External intrusion. Kinetic signature approaching. Unknown technique class. Instinct alert triggered. Suggest defensive stance.]
"Something's coming," Rex muttered, eyes narrowing.
Luffy tilted his head. "Huh? I don't hear anything—"
Then the air screeched.
From the far end of the chamber, a humanoid figure appeared — cloaked in silver-gray armor, mask carved from bone, eyes like hollow glass.
The figure moved without hesitation.
It launched forward — sword raised.
"MOVE!" Rex shouted.
The blade collided with stone where they stood a moment ago, slicing clean through.
This wasn't Baroque Works.
This was something older. Something called by the shrine itself.
"Wh-What is that?!" Usopp shouted, backing away.
"I don't know," Luffy said. "But I wanna punch it!"
Rex stood between them and the masked warrior. "No. I'll handle this."
The Clash – Rex vs. the Shrine Guardian
The enemy's blade came again — silent, fast.
Rex sidestepped, spun, and launched a flurry of counters — elbows, kicks, and a palm to the ribs. The masked figure took the hit and barely flinched.
It leapt back, feet skating across the sand-polished stone.
Then it charged again — faster, heavier.
Rex needed force.
And so…
He raised one hand.
Energy began to spiral in his palm.
Blue.
Violent.
Condensing.
A swirling ball of rotating energy that buzzed like a dying sun.
Luffy and Usopp stared.
"What's he doing…?" Luffy asked.
"I don't know!!" Usopp shouted. "It's not Haki! It's not a Devil Fruit!"
Rex dashed forward—
"Rasengan."
He slammed the spiraling orb directly into the enemy's chest.
BOOM—!
The masked warrior was launched across the room, crashing into a pillar with a thunderous crack. The stone shattered.
Usopp's jaw hit the floor.
"What—WHAT WAS THAT?!"
Luffy's eyes lit up. "THAT WAS AWESOME!! DO IT AGAIN!!"
The smoke cleared.
The enemy stirred again.
Still not down.
Rex exhaled slowly.
"Alright. Then let's evolve."
He snapped his fingers — and two clones of himself appeared beside him, dust swirling as they rose.
"Shadow Clone Technique."
Luffy gasped. "WHOA!! MORE OF YOU?!"
"Don't get used to it," Rex said with a grin.
The two clones launched forward, attacking with synchronized patterns while Rex weaved through the space behind the enemy.
The masked warrior sliced through one clone — poof.
The second struck with a feint — and was countered.
That was the moment.
Rex leapt into the air, hand pulsing with blue lightning, crackling between his fingers like the sky had been captured in his palm.
"Chidori."
He dove down, electricity screaming in his wake—
SHUNK.
The lightning-charged strike pierced the mask and shattered half of it.
The figure stumbled.
Finally, it let out a screech.
But it wasn't defeated yet.
It raised both hands and unleashed a roar of cursed wind.
Rex skidded back, hair tousled, coat torn.
His voice dropped low.
"…Time to go bigger."
He raised his palm again.
A new shape formed.
Not just a sphere this time—
But a shuriken, spinning, burning with cutting chakra-infused energy.
"Rasen Shuriken."
Luffy took a step back. "That looks dangerous even for me."
"Exactly," Rex said.
He hurled the shuriken.
It didn't explode.
It tore.
The air split as the spinning blade sliced through the chamber — catching the masked figure mid-dodge and detonating in a vortex of wind and light.
Stone cracked.
Dust flooded the chamber.
Silence followed.
And when it cleared — the enemy was gone.
Only shattered fragments of its blade remained.
Aftermath
Usopp ran up to him, panting. "WHAT—WHAT WAS ALL THAT?! Those weren't Devil Fruits! That wasn't Haki! That wasn't ANYTHING I've seen!!"
Luffy just stood there, stunned.
"That was like… something from another world."
Rex smiled faintly, wiping dust from his sleeve.
"Yeah."
Usopp blinked. "Wait—so you've been hiding THAT this whole time?"
"I wasn't hiding," Rex said, smirking. "Just… saving it."
Luffy laughed. "You're gonna have to teach me that spinny thing!"
"…Maybe later."
Somewhere Far Above – On a Cliff Near Alubarna
A Baroque scout had seen it.
Just a flicker of energy… from underground.
He turned to his Den Den Mushi in terror.
"…Sir. Something's wrong. He's not normal. He's—he's using abilities we don't even understand."