Hellish Body Tempering, the Brothers' Muscles Could No Longer Be Hidden

"AAAAAAAAH—!"

Accompanied by Sabo's hoarse, shrill scream, the sky over Mount Colubo seemed to have been dyed a hopeless gray.

From that day onward, the ASL Brothers officially began their sunless "lightning devil training" atop this mountain far removed from civilization.

Time flew by like a galloping white horse.

In the blink of an eye, five years had passed.

Sea Circle Calendar 1508.

Deep within Mount Colubo, on a massive clearing that had been forcibly leveled.

"Bang! Bang! Bang!"

Dull, crushing sounds of flesh colliding rang out densely like war drums, shaking leaves from the surrounding trees.

The air was thick with the pungent scent of male hormones and salty sweat.

Three boys, bare from the waist up and wearing nothing but tattered shorts, were savagely beating each other at a terrifying speed beyond the limits of ordinary vision!

That was right—they were beating each other senseless!

There were no fancy techniques, only the purest violence: fists meeting flesh, every blow aimed to kill!

These three little brats, once as skinny as monkeys, had undergone horrifying physical mutations after five years of hellish torment!

"Rubber-Rubber—"

Twelve-year-old Monkey D. Luffy let out a beast-like roar.

He suddenly took a deep breath, and his seemingly normal body underwent an outrageously exaggerated transformation!

The muscles all over his body swelled and bulged, as though they had been inflated!

Those rubber cells that should have been soft and elastic had become as hard as steel after five years of repeated lightning-fueled tearing and reconstruction!

Luffy did not even need to pump himself up into a Gear like he had in the original story.

He merely flexed, and his sharply defined pectorals, washboard eight-pack abs, and terrifyingly thick biceps seemed to burst the air apart!

"Take this, Ace!"

Luffy threw out his right fist, the sheer force creating a sonic boom in the air!

With a deafening "Bang!", airwaves rolled outward!

"Don't get cocky, Luffy!"

Fifteen-year-old Ace's gaze was as cold and sharp as a blade. Without retreating an inch, he met Luffy's fist with one of his own!

Ace had now grown to a height of 1.75 meters.

The immaturity of his youth had faded away, replaced by a perfect inverted-triangle physique like that of a Greek sculpture, brimming with explosive power!

His muscles were sleek and firm, containing terrifying explosive force capable of tearing apart tigers and leopards.

Their fists collided!

There was no Devil Fruit power involved—just a pure clash of flesh and strength!

"Boom!"

A violent shockwave swept outward from the two of them, instantly blasting up sand and rocks from the ground!

The hard rock beneath their feet cracked into dense spiderweb-like fractures from the recoil!

"Hey, hey, don't forget about me!"

A blond boy wearing black goggles darted in from the side like a ghost!

It was fourteen-year-old Sabo.

Compared with Luffy's wildness and Ace's ferocity, Sabo's muscles appeared more restrained and compact.

But his tightly packed, sinewy physique exuded the same extremely dangerous aura of a predator.

"Take this! Dragon Claw Fist!"

Sabo formed his right hand into a claw. His fingers possessed astonishing power as they tore through the air with a sharp whistle and viciously grabbed at Ace's shoulder!

The technique he had developed in the Gray Terminal had, under Lei En's modified guidance, begun to display the terrifying power to crush steel.

The three instantly descended into a chaotic melee, fighting fiercely without a clear victor as fist winds howled and force burst in every direction!

On a flat boulder not far from the clearing.

Fifteen-year-old Lei En was lazily reclining against the back of a chair.

He had fully grown into his frame now, nearing 1.8 meters tall. His black trench coat hung open, revealing firm but not overly exaggerated muscular lines beneath.

Holding a cup of black tea that Dadan had just brewed, he leisurely took a sip. In his deep black eyes, the three "monsters" below who were punching out sonic booms were reflected.

"Mm... not bad. These muscle lines, this explosive power—they've got about half of what I had back then."

Lei En nodded in satisfaction.

Over the past five years, besides giving the three brats "deep therapy" with electric currents of different voltages every day.

He had also traveled everywhere to capture massive Sea Kings and ferocious beasts, using them as living punching bags for the boys.

Coupled with those specially made Seastone weights that increased in weight every day...

He had forcibly trained these three, who were originally suited for speed or Devil Fruit abilities, into muscle-bound tyrannosaurs capable of crushing people their age hundreds of times over with their bodies alone!

The current Luffy could punch straight through an ordinary East Blue pirate ship with one blow, even without eating the Rubber-Rubber Fruit!

Not to mention Ace and Sabo. Their martial arts skills had probably already reached the threshold of a Marine Headquarters rear admiral.

"Stop!"

Lei En set down his teacup. His voice was not loud, yet it entered the ears of the three who were fiercely battling with perfect clarity.

"Whoosh!"

Luffy, Ace, and Sabo seemed to have heard some terrifying curse. Their bodies instantly froze midair, then they landed neatly in front of Lei En in perfectly standard attention stances.

They panted heavily, sweat flowing down their solid muscles, yet their eyes were filled with extreme awe for Lei En.

"Boss, we fought three thousand rounds today. Nobody lost, and nobody won!" Luffy wiped away his sweat and grinned, revealing a mouthful of white teeth.

"Idiot. If I hadn't held back, I'd have knocked you down long ago!" Ace curled his lips in annoyance.

"Give it up, Ace. If you hadn't dodged so quickly just now, my Dragon Claw Fist would have crippled your arm." Sabo pushed up his goggles and mercilessly exposed him.

Lei En raised an eyebrow at the three who were still bickering.

"Enough. Stop arguing."

Lei En stood up, jumped down from the boulder, and walked over to them.

He reached out and knocked on Luffy's chest muscles, which were as hard as iron, producing dull "thump, thump" sounds.

"Your foundation is more or less set. Your durability and strength barely count as passing."

Upon hearing the word "passing," all three secretly breathed a sigh of relief.

Heaven knew how they had survived these five years!

"However..."

Lei En's tone shifted, and his gaze deepened.

"There is a limit to body tempering. You may have enough strength now, but against true experts, you're still just a bunch of reckless fools with brute force."

From his system storage, he pulled out three enormous pitch-black iron blocks that radiated a suffocatingly heavy aura!

"Boom! Boom! Boom!"

Lei En casually tossed the three iron blocks onto the ground, and the entirety of Mount Colubo seemed to tremble!

Each of the three iron blocks was as large as a small hill! And they were all forged from high-purity Seastone!

"W-What are those?!"

Luffy stared at the three black mountains, his legs instinctively going weak. Under the oppression of the Seastone, the power of his Rubber-Rubber Fruit began to ache faintly.

"These are your 'summer homework' for the next few years."

Lei En clapped his hands and looked at the horrified trio, a particularly sinister smirk curling across his lips.

"I have some personal business to attend to. I'm heading out to sea to have some fun, and I'll take a stroll around the Grand Line while I'm at it."

He pointed at the three Seastone blocks, his tone leaving no room for doubt.

"When I return, if you still can't carry those things on your backs and run a marathon across the seafloor..."

Blue arcs of electricity that made their souls tremble once again danced between Lei En's fingers.

"Then I'll fry all three of you into roasted whole lamb!"

With that, Lei En turned around and ruthlessly headed down the mountain, leaving them only with his carefree silhouette.

Luffy, Ace, and Sabo stared at the mountain-like Seastone blocks, swallowed hard, and felt like crying without tears.

"Boss... you're trying to kill us..."

Just as the three wailed in despair, Lei En's leisurely voice drifted over from afar on the wind.

"Oh, right. If you run into a one-armed drunkard named Red-Hair while I'm gone, tell him for me..."