Hardcore Child-Rearing, Day One: Luffy Howled After Being Electrocuted

"AAAAAHHHH—!"

Early morning on Mount Colubo should have been a peaceful time filled with birdsong and flowers.

Yet today, wave after wave of piercing screams exploded through the air like wailing ghosts, scaring the wild boars in the forest into moving out overnight.

Bang!

A small, skinny figure wearing a straw hat flew through the air like a kite with a broken string, tracing a crooked arc before crashing heavily into a massive tree thick enough for two people to wrap their arms around.

Leaves rustled down.

Luffy clutched his head and grimaced as he crawled up from the ground.

His usually carefree face was now filled with the despair of someone questioning his entire life.

"It hurts! It hurts so much! What the hell are you doing?!"

Luffy protested loudly, tears already welling up in his eyes.

Not far away, Lei En sat atop a flat boulder.

He had not even bothered to stand. He simply lounged with one leg crossed over the other, idly twirling a small branch he had snapped off somewhere.

At the tip of the branch, a faint yet dazzling dark-blue electric arc crackled like a venomous snake flicking its tongue.

"What am I doing? Training you, of course, future Pirate King."

A sinister smile curled across Lei En's lips, his voice brimming with mockery.

"This is the first phase of the course I designed specifically for you—extreme endurance training."

"What kind of training is this?! I'm a rubber man!"

Luffy shouted indignantly, even yanking his cheek out hard as if showing off his Devil Fruit ability.

"Rubber is an insulator! Your electricity can't do anything to me!"

He craned his neck, trying to refute this terrifying instructor with his pitiful grasp of physics.

"Can't do anything?"

Lei En could not help but laugh, as though he had just heard the biggest joke in the world.

"How naive. Too naive."

He jumped down from the boulder and slowly walked over to Luffy.

"Luffy, didn't your grandpa ever teach you that relying too much on Devil Fruit abilities will get you killed horribly on these seas?"

Lei En crouched down. Looking at Luffy's still stubborn expression, his eyes gradually turned cold and deep.

"Insulators indeed do not conduct electricity."

"But I'm the Thunder God. And you want to talk physics with me?"

Lei En extended the branch crackling with electricity and lightly touched it to Luffy's shoulder.

"Let me teach you what high-frequency electromagnetic vibration is."

The instant he finished speaking!

The electric arc at Lei En's fingertip abruptly changed frequency. It was no longer a violent discharge of current, but an incredibly high-frequency microscopic vibration!

Bzzzzz—!

The vibration directly ignored the insulating rubber layer on Luffy's skin, stabbing into his muscle fibers and nerve endings like countless invisible needles as thin as strands of hair!

"Ugh, aaahhh—!!!"

Luffy, who had been acting so cocky a moment ago, suddenly stiffened all over like an electrocuted frog and let out a bloodcurdling scream!

Pain!

Bone-piercing, marrow-scraping pain!

This pain did not act on the surface at all. It erupted directly from inside his body, as if tens of thousands of ants were gnawing on his bone marrow!

Luffy rolled wildly through the dirt, clutching his head with both hands. Even his straw hat flew off to the side.

His prized rubber body had become a complete joke before this utterly unreasonable "modified electric therapy."

"Waaah... It hurts! Grandpa! I'm telling Grandpa on you!"

Luffy cried and shouted while twitching.

"I want to be a pirate! I don't want you training me anymore! You're a big liar! A big demon!"

Watching Luffy roll around in the mud like a mud monkey, Lei En not only failed to stop, but smiled as he withdrew the branch.

"Go find old man Karp? He's probably eating rice crackers right now and thanking me for disciplining his grandson."

Lei En stood and dusted off his hands.

"Stop crying. This is only the beginning."

He raised a finger, and electric arcs began to dance from its tip once more.

"That was just the appetizer. Now, increase the voltage by ten volts."

"Don't—!"

For the entire day that followed, the mountain bandits of Mount Colubo lived in extreme terror.

Dadan hid inside the cabin, covering her ears with both hands as she trembled.

She had lived for so many years, killed people and robbed goods, but she had never seen such perverse, such utterly deranged methods of torture.

This was truly training someone to death!

Ace had also been forced into the training, but because his physique differed, Lei En had assigned him another hellish course of "physical destruction and rebuilding." At that moment, he lay unconscious in a pit on the other side.

It was not until the sun set.

That the screams finally began to fade.

Luffy lay spread-eagled in the mud, his entire body charred black and his clothes reduced to strips of rags.

His eyes had rolled back, foam dribbled from his mouth, and his body occasionally twitched unconsciously. He had clearly been shocked so badly that he no longer had the strength to scream.

"Whew... We'll call it here for today."

Lei En stretched, walked over to Luffy, and lightly nudged his limp arm with the tip of his foot.

It was a horrific sight.

Yet a trace of intense surprise gleamed in Lei En's eyes, which had awakened Observation Haki.

Because he could clearly "see" it!

Inside Luffy's nearly collapsed body, those rubber muscle cells that had repeatedly been torn apart and destroyed by the high-frequency current had not simply died.

Instead.

Under the combined effects of some incredibly tenacious vitality and the Rubber-Rubber Fruit's properties.

They were undergoing a mutated reconstruction and strengthening process at an extremely slow, yet visible pace!

Their density was increasing!

Their toughness was growing stronger!

It was practically like undergoing a complete rebirth!

"Damn... This kid's vitality really is like a cockroach's."

Lei En clicked his tongue to himself.

At this rate, in less than three years, this kid would become a muscular tyrannosaur capable of smashing a warship with one punch through sheer physical strength, without even activating a Gear!

"Looks like this devil training is working even better than I expected."

Lei En smiled in satisfaction and turned to look at the dilapidated bandit cabin in the distance.

"Hey, fatty in there."

His voice was not loud, but it reached Dadan's ears clearly.

"Carry these two brats inside. Use the best medicine you have to treat them, prepare more meat, and we'll continue tomorrow."

Dadan did not dare utter a single word of refusal. She scrambled out with several subordinates and carefully carried Luffy and Ace inside as though transporting corpses.

Late at night.

Mount Colubo finally returned to peace.

Lei En sat alone at the edge of a cliff, watching the stars fill the sky as he tossed the Cloud-Cloud Fruit he had taken from Enel in his hand.

Just as he was considering how to torment those two brats next.

His sharp Observation Haki suddenly caught a set of extremely faint footsteps in the forest behind him, along with deliberately suppressed breathing.

"Oh?"

Lei En did not turn around. He merely stopped tossing the fruit, a teasing smile curling across his lips.

"Coming to see your demon instructor instead of sleeping in the middle of the night? You don't want your little pipe anymore?"