Days after days under the fierce, unforgiving sun of Rusukaina Island. The initial euphoria of training faded into a painful, exhausting grind. Rayleigh had gone back to Sabaody to see Shakky, leaving the two pupils alone to face the island's brutal ecosystem.
Luffy was making monstrous progress. His screams of frustration were often followed by the sharp, echoing crack of his black-armored fist connecting with stone, evidence of his innate will forcing the Haki to obey.
Leo, however, was stuck. He gained experience in tiny, frustrating increments, his Level moving at a snail's pace. He killed dozens of wolves and giant centipedes, yet the Haki line on his System remained stubbornly Locked.
I need a higher-level mob. This grind is useless, Leo thought, trekking deeper into the densest, most treacherous part of the forest—an area Rayleigh had explicitly warned them to avoid alone.
Suddenly, the dense canopy fell away, and Leo found himself in a clearing marked by massive claw marks on the surrounding trees. A low, territorial rumble vibrated through the air, silencing the jungle birds.
Then it emerged: a colossal Jungle Lion, its mane the color of dried blood, muscles corded like steel cables, and eyes burning with malice. It was easily twice the size of any monster Leo had fought so far.
Leo froze, a cold wash of military panic hitting him. This is not a monster; this is a boss fight.
He instinctively flicked his wrist, summoning the System Interface.
DING!
Power Abilities (1) (Guardian Shield - Cooldown: 0 days, 0 hours, 0 minutes - READY!)
Leo saw the READY notification, but a familiar stubbornness kicked in. No. I will not waste a legendary, Admiral-stopping shield on a single beast. If I can't beat this with my own hands, I don't deserve the next level.
The lion didn't wait. It surged forward, a terrifying blend of speed and mass. Leo barely had time to raise his Kukri knife before the lion's massive paw slammed into his chest.
CRACK!
Leo was sent tumbling backward, skidding across the dirt, the air exploding from his lungs. The pain was immediate, sharp, and blinding.
Health: 70/100
Too durable! Leo coughed, struggling to draw a ragged breath. My Kukri can't pierce its hide! I need more force!
He scrambled back, adrenaline overriding the searing pain. He lunged forward, trying to stab the Kukri into the lion's flank, but the blade only glanced off the beast's thick hide, leaving a shallow, meaningless scratch.
The lion, enraged by the prick, delivered a sweeping rake of its claws across Leo's torso.
RIP!
Leo screamed as he felt skin and muscle tear. He fell to his knees, clutching his side,
Health: 50/100
He remembered Rayleigh's calm, powerful voice from that first lesson: "Don't just use force. Think of your will turning into an armor around your hands."
With the Jungle Lion preparing to pounce again, its mouth wide and its roar deafening, Leo felt a desperate surge of fury—not at the monster, but at his own weakness, at the unfairness of the world, at the Locked System line.
I am a survivor! I survived Akainu! I will not die to a cat!
He focused every bit of his desperate will onto his right forearm, forcing the very essence of his spirit to condense.
SHHHHKK!
In an instant, his arm was enveloped in a profound, glossy black sheen. The Kukri knife in his hand also turned obsidian, becoming sharp, hard, and utterly unforgiving.
DING!
The System exploded with notifications.
CONGRATULATIONS! HOST ( HAKI UNLOCKED: ARMAMENT (BUSOSHOKU)
Leo stared at his black-armored arm, a fierce, triumphant grin splitting his bloodied face. "Yes! Finally! Now I'll show you the power of a transmigrator!"
The lion roared, attacking with renewed aggression, its paw aiming for a crushing strike. Leo met the attack, not by dodging, but by jumping directly onto the descending paw. His Armament-coated Kukri found purchase on the lion's tough hide, and Leo used the momentum to leap straight towards the monster's head, driving the blade into its vulnerable left eye.
The lion shrieked—a sound of pure agony and confusion—rearing up on its hind legs, blindly swinging its paws.
Leo, agile now with the boost in his stats, was a blur. He dodged the massive, panicked swipes, the scent of fear and blood driving him forward. He saw an opening in its side, and with a swift, Haki-laced movement, plunged the Kukri knife deep into its flank.
The lion, defeated and terrified, tried to run, dragging its wounded body away from the nightmare figure that had turned its own strength against it.
But Leo didn't stop. He vaulted onto the lion's back, using the Armament-coated Kukri to anchor himself, and with a final, primal yell, he drove the blade deep into the back of the lion's skull, ending the brutal fight instantly.
Leo collapsed next to the enormous carcass, his body still shaking, sweat mingling with the lion's blood and the lingering metallic taste of his own injury.
"Hah... huff... finally," Leo wheezed, managing a tired, exhilarated smile. "I defeated a big monster. I did it on my own."
The System recognized the achievement.
DING!
Objective Complete: Defeat Jungle Lion (Unscripted Boss ) XP GAINED: 50 Level Up!
Leo immediately summoned the interface, his eyes widening in shock and relief at the new stats.
Leo's Current System Status
Host: Leo (Level 7)
XP: 0/500 (0% to Level 8)
Authority Points: 1000
Core Attributes
Health: 25/100
Stamina: 15/100
Attack: 50 (Significant jump due to Haki Unlock)
Defense: 25 (Base Defense)
Unlocked Abilities
Haki: Armament (Mastery 15%) UNLOCKED!
Power Abilities: 1 (Guardian Shield - Use Remaining: 2)
My Level and stats have exploded! And the Shield cooldown is gone! Leo thought, his heart soaring. This is how you grind! You fight a high-level boss!
The realization that he had unlocked Armament Haki through sheer will, independent of the System's Level requirement, was the most satisfying reward of all.
Leo pushed himself up, every muscle screaming in protest, the scent of his own blood heavy in the air. He was Level 7, a Haki user, but he was also deeply wounded and barely able to stand
"Now," Leo grunted, slowly putting one heavy foot in front of the other, "let's go find Luffy. I finally have something to show that monster... if I don't collapse first."
Author's Note
Hey everyone, thanks for sticking with Leo's grind! You may have noticed that the anime doesn't show the full two years of training on Rusukaina Island—for obvious reasons, it'd be pretty dull! So, I'll be focusing the remaining training chapters solely on key milestones, breakthroughs, and System progress, as well as some humorous moments between Luffy and Leo, rather than showing every day-to-day event. We'll skip the unnecessary filler and jump right to the important developments!
Rest assured, the plot will accelerate dramatically once the time-skip is complete and Leo sets sail.
> I will be dropping one bonus chapter for every 10 reviews. Comment.
> One bonus chapter will be released for every 20 powerstones.
> You can read advanced chapters ahead on Patreon if you're interested :
patreon.com/kazama677