One piece: But MC is smart.

The jungle clearing echoed with the sound of crashing blows and the rustle of leaves as Shadow faced Luffy for another intense training session. It had been 10 days of relentless sparring, pushing Luffy to his limits as he honed his Gear 2 and Gear 3 techniques under Shadow's sharp, unyielding guidance.

"Alright, Luffy," Shadow said, his calm voice contrasting with Luffy's wild energy. "Show me what you've got. Use everything."

Luffy grinned, bouncing on his feet. "You're gonna regret saying that! Gear… Second!"

Steam hissed from Luffy's body as he accelerated his blood flow, his muscles visibly tensing. He vanished in a blur of speed, appearing beside Shadow with a smirk. "Gum-Gum Jet Pistol!"

Shadow's Observation Haki kicked in, allowing him to predict the strike. He sidestepped the punch effortlessly, Luffy's fist crashing into a tree behind him, splitting it in two.

"Too slow," Shadow said, unimpressed.

"Fine, how about this? Gum-Gum Jet Bazooka!" Luffy shouted, thrusting both fists forward with explosive force.

Shadow ducked low, moving with such precision that Luffy's fists barely grazed the air. Before Luffy could pull back, Shadow closed the gap, placing a hand on Luffy's shoulder and redirecting him off balance. Luffy stumbled, spinning comically before regaining his footing.

"Oi! That's cheating!" Luffy huffed, puffing his cheeks in frustration.

"It's not cheating. You're just predictable," Shadow replied, his tone dry.

Luffy growled and launched into the air. "Then try dodging this! Gum-Gum Jet Stamp!" His leg stretched high before slamming down like a hammer.

Shadow sidestepped once again, letting Luffy's foot hit the ground with a loud crash, creating a small crater. Before Luffy could react, Shadow appeared beside him, tapping his forehead lightly with a knuckle.

"Pay attention," Shadow said, stepping back.

Luffy gritted his teeth, his frustration mounting. "Alright, you asked for it! Gear… Third!"

Luffy bit into his thumb, inflating his arm to massive proportions. "Gum-Gum Gigant Rifle!" he shouted, slamming the colossal fist toward Shadow.

Shadow's eyes narrowed as he activated Armament Haki, coating his hands to redirect the enormous punch with a controlled movement. The ground beneath Shadow cracked, but he remained steady. Luffy, on the other hand, stumbled from the recoil, deflating and collapsing in exhaustion.

"Why does Gear Third keep doing this?!" Luffy whined, sprawled on the ground.

"Because your body isn't strong enough yet," Shadow said bluntly. "Your stamina is too low to sustain these techniques. That's why you're left vulnerable after every attack."

Luffy groaned, rolling onto his back. "But I'm hungry…"

Shadow smirked beneath his mask. "If you let me train your body like mine, you'll build great stamina. You'll also be able to eat a lot of meat to recover."

At the mention of meat, Luffy's eyes sparkled. "Meat? How much?"

"As much as you want," Shadow replied, his voice carrying a trace of amusement.

"Deal!" Luffy shouted, jumping to his feet. "Train me, Shadow! I'll do whatever you say if it means more meat!"

Shadow chuckled inwardly. "This kid... pure chaos, but his potential is limitless."

As the sun dipped below the horizon, marking the end of their training for the day, Shadow couldn't help but feel satisfaction. Luffy's techniques were far from perfect, but his growth over the past ten days was undeniable. With the right training, Luffy would surpass even the expectations of the Grand Line.

"Rest up, Luffy. Tomorrow, we start the real training," Shadow said, walking into the shadows of the jungle.

"More meat tomorrow too, right?" Luffy called after him.

Shadow didn't respond, but a faint smirk crossed his lips as he disappeared into the night.

Under the shade of the jungle, Rashed worked silently, his hand hovering over Luffy's chest as a faint glow emitted from his palm. Using his Energy Manipulation technique, he guided waves of energy through Luffy's body, tempering his muscles, bones, and even the elasticity of his rubber-like physiology.

Luffy, lying on the ground and staring at the sky, mumbled through a mouthful of meat, "You really can do anything, huh? You've even got a power to make meat appear outta nowhere!"

Rashed glanced at him, amused by Luffy's sheer simplicity. In truth, Rashed had spent nearly 100 million Berri from the system to purchase massive quantities of meat and nutrients. Luffy's body seemed insatiable, absorbing everything he fed it at an astonishing rate. "Just how much can this guy eat?" Rashed thought, watching Luffy wolf down a mountain of meat for the fifth time that day.

What amazed Rashed even more was Luffy's potential. Unlike a normal human body, Luffy's rubber physiology allowed his muscles and bones to compact in ways Rashed had never seen before. With every wave of energy Rashed sent through him, Luffy's body responded almost immediately, growing stronger and denser, far beyond Rashed's expectations.

"This kid's potential… it's greater than mine," Rashed mused, momentarily awestruck. "His rubber-like structure allows for unparalleled flexibility and compact strength. No wonder he eats so much—his body burns through nutrients like a furnace."

20 Days of Training

For the next 20 days, Rashed devoted himself to training Luffy's body. Every session was intense, tailored specifically to Luffy's unique physiology using Rashed's exclusive, individualized teaching technique. He pushed Luffy through relentless conditioning and drilled him on the basics of Armament Haki, honing his focus and teaching him how to channel his willpower into physical strength.

By the end of the 20th day, Luffy stood in the clearing, examining his transformed body. His once-lanky frame was now covered in defined muscles, his abs etched like stone. Every movement felt powerful, his body emitting a strength he couldn't even fathom before.

"This is insane!" Luffy exclaimed, flexing his arms. "I'm so much stronger now!"

Rashed stood nearby, arms crossed, his expression unreadable. "Your body is as strong as it'll ever need to be. There are no more side effects from your Gear 2 or Gear 3 now. You can push your techniques as far as you want without breaking down."

Luffy's eyes widened. "So… that's why I couldn't scratch you before. Your body is 20 times stronger than mine was! But now…" He clenched his fists, determination glowing in his eyes.

As he stood there, something deep within him stirred. An unknown power rippled through his veins, faint but unmistakable. His newly tempered body seemed to awaken a latent potential, something waiting to be unleashed.

Luffy stared at his fists, his jaw set with newfound determination. "If I want to be the King of the Pirates, I have to face enemies as strong as you… maybe even stronger," he muttered, glancing at Rashed.

He straightened up, his resolve solidifying. "That's it! I'm gonna master that black-hand technique you call Armament Haki. And that eye-move thing too—the Observation Haki! When I do, I'm gonna beat you!"

Rashed smirked faintly beneath his mask. "We'll see."

With his body stronger than ever and his mind set on mastering Haki, Luffy's ambition burned brighter than ever. He was ready to face any challenge, and most importantly, he was determined to defeat Shadow—not just to prove himself but to convince him to join the crew.

As Rashed turned to leave the clearing, Luffy called after him, "Hey, don't think you're off the hook! Tomorrow, I'll be even stronger!"

Rashed didn't respond, but his thoughts betrayed him. "This kid… he's growing faster than even I expected. If I can push him far enough, he'll surpass anything the Grand Line throws at him. But for now, let him think it's just a fight."

He disappeared into the jungle, leaving Luffy alone with his thoughts, his new body, and his unshakable dream.

Luffy sat cross-legged on the sandy shore of Foosha Village, a faint breeze brushing against his straw hat as he stared out at the horizon. His mind, for once, wasn't on adventure or treasure but on the masked man who had turned his world upside down.

"Alright, think, Luffy," he muttered to himself, tapping his temple. "Rashed is strong. Way too strong. He's faster than me, he dodges everything, and his punches hurt even though I'm rubber… What can I do?"

He clenched his fists, recalling the Armament Haki Shadow had taught him. "I need to use this better. If I can cover my fists with this black stuff and hit harder, maybe I can land a real punch on him!"

Luffy swung through the dense jungle, his body buzzing with energy. The trees blurred past him as he moved faster than ever, his newfound strength making every leap and swing feel effortless. He spotted a massive boulder near a clearing and grinned.

"Let's see what this body can do!" he shouted, his voice echoing through the trees.

Planting his feet, Luffy activated Gear Second, steam hissing from his body as his blood accelerated. He coated his fists with the faint black sheen of Armament Haki, the technique still rough but undeniably there.

"Gum-Gum Jet Bazooka!" he roared, slamming both fists into the boulder. The rock exploded into fragments, the sheer force of the attack sending shockwaves through the jungle.

Luffy stared at the rubble, his jaw-dropping in amazement. "Whoa! That was awesome!"

He laughed, leaping into the air. "This new power is incredible! I'm stronger, faster, and I can hit way harder now!"

After hours of training, Luffy plopped onto a large root, devouring a mountain of meat he had prepared earlier. His grin stretched from ear to ear as he patted his now-full belly.

"Shadow really knows his stuff," he mumbled through a mouthful of food. "I feel amazing! Like I could take on the whole world!"

The thought of his strength growing so quickly filled him with pride. For the first time, he could imagine standing toe-to-toe with enemies as strong as Shadow—or even stronger.

"I'm gonna beat him," Luffy declared, his eyes gleaming with determination. "And when I do, he'll have no choice but to join my crew!"