Before awakening Nen, Gon could push a three-hundred-pound man several dozen meters with raw muscle. Now, with his aura nodes open, his physical strength had multiplied.
Killua was even more terrifying. Before learning a single Nen technique, he had possessed the monstrous strength required to open the Zoldyck Testing Gate.
Gon gasped for air, dropping the colossal supply sack with a thud that shook the ground. He looked at the top of the bag, but Killua was gone.
He glanced forward and saw the white-haired boy strolling toward him from the distance, waving casually as if he hadn't just been riding on Gon's back.
"Yo, Gon. Welcome back."
"Killua!" Gon ignored the casual greeting entirely, his eyes burning with curiosity. "How did you make your body heavier just now? Tell me!"
"It's simple physics," Killua shrugged, shoving his hands in his pockets. "Your 'weight' isn't just mass. It's mass plus force. When you're standing still, you're just heavy. But if you apply downward force at the moment of impact or movement, you effectively increase your weight. That's how you sent that fat guy flying at the Exam."
Gon blinked. The theory clicked instantly. He had done it instinctively before; hearing it explained made the mechanic clear.
"Kyle," Gon turned to the older boy, looking around at the pirates who were now busy clearing the forest. "Why do we need so many people?"
"For your training," Kyle replied, his gaze sweeping over the makeshift camp. "We're not just practicing Observation Haki. We're laying the foundation for Armament Haki and reinforcing your Nen basics."
Kyle knew the reality: beating Hisoka in fourteen days was a pipe dream. The Magician was a veteran floor master.
But victory wasn't the only goal. Kyle needed to bait Hisoka. If he could intrigue the battle-crazed clown enough to lure him into the One Piece world, Hisoka would become the ultimate battery. In this dimension, the Resonance Contract would allow Kyle to harvest power from Hisoka's battles—and perhaps, even his death—without losing the gains if Hisoka died back in the Hunter world.
"So, what's the plan?" Killua asked, cracking his knuckles.
"Observation Haki is simple in theory," Kyle explained. "Blindfold yourself. Rely purely on your senses to dodge. You don't stop until you can dodge everything."
"Sounds fun." Killua grabbed a strip of cloth and tied it over his eyes.
Gon grinned, picking up a sturdy branch. "I'm coming for you, Killua!"
"Bring it."
Whoosh.
Gon swung for the head.
Killua didn't panic. The branch displaced air as it moved. To an assassin trained to hear a pin drop in a thunderstorm, the sound of the swing was as loud as a siren. He tilted his head slightly. The wood whistled past his ear.
Kyle watched, unsurprised. Killua's assassin training had already wired his brain to detect subtle environmental shifts. This was practically the prototype for Observation Haki.
Gon, seeing his friend adapt so quickly, felt his competitive streak flare up. "Okay, faster then!"
The swings blurred. Swish, swish, swish.
The sound of tearing air filled the clearing. Yet, Killua moved like a leaf caught in a gale—erratic, weightless, and untouchable. With every dodge, a new sensory organ seemed to open in his mind. The reliance on sound faded, replaced by a pure, formless intent.
A pirate, pausing to wipe sweat from his brow, dropped his axe. His jaw hit the floor.
"H-Hey... look at that kid! He's blindfolded!"
The other pirates froze, watching in stunned silence. The speed was impossible. The precision was inhuman.
As expected, Kyle thought. Killua's combat foundation is leagues ahead of Gon.
"Alright, pause," Kyle called out. "Killua has the basics of Observation down. But for the next ten days, our priority is Armament."
"How is that different from Ken?" Killua asked, pulling off the blindfold.
"Similar principle—defense and offense enhancement," Kyle explained. "But the source is different. Ken uses aura. Haki uses spiritual willpower. If you stack them... your defense becomes an iron fortress."
He tapped his chest. "Step one is extreme physical conditioning and impact resistance. Slamming into trees, taking hits. Step two is mental control—flowing your will into your skin."
Gon's eyes began to spin. Steam practically shot out of his ears. "Will... flow... energy? Kyle, can't you just tell me how many rocks to break?"
Killua, however, nodded slowly.
Kyle looked at the assassin. Killua had spent his childhood being electrocuted, whipped, and poisoned. His body was already a tempered weapon. In this world, he was essentially standing at the door of Armament Haki, waiting for the key.
And he found it quickly.
By the end of the first day, a strange, metallic sheen flickered over Killua's right hand.
"This is it!" Killua stared at his fist, which had turned a deep, obsidian black. "This is Armament Haki! If I layer Ken on top of this..."
"Let's test it," Kyle stepped forward, his own arm blackening instantly.
The two clashed.
BOOM.
It didn't sound like flesh hitting flesh. It sounded like two cannonballs colliding. The air shockwave kicked up dust around them. They moved faster, trading blows that would have shattered normal bones.
Thirty minutes later, they broke apart, both grinning, sweat dripping from their faces.
"That felt amazing," Killua panted.
Kyle nodded. Through the resonance, he retained the experience from both sides of the fight. His proficiency was skyrocketing.
"That was awesome!" Gon shouted from the sidelines, bouncing on his heels. "I want to try! Fight me!"
Killua looked at Kyle. "Me or you?"
Kyle laughed, stepping back. "You take this one. Go easy on him."
"Heh. Sure," Killua smirked, a devilish light in his eyes. "I'll be gentle."
Another thirty minutes passed.
Gon lay on the ground, beaten black and blue, his face swollen. But his eyes were shining.
"How was it?" Kyle asked, looking down at the battered boy. "Did you feel the threshold?"
"Mmph... yup," Gon mumbled through a swollen lip. "I felt it. Just a little bit more..."
Kyle smiled. Gon was a simple creature. He didn't learn through lectures; he learned through pain. His hyper-focus allowed him to analyze the sensation of getting hit and reverse-engineer the power behind it. It was a brutal, reckless method, but for an Enhancer like Gon, it was the only way.
For the next week, the pirates found themselves promoted from laborers to training dummies. Their job was simple: pick up logs and hit the boys. Over and over again.
Day by day, the metallic sheen on Gon's skin grew more consistent.
By the tenth day, both boys could summon basic Armament Haki at will.
The training camp ended. They packed their gear, released the terrified pirates, and stepped back through the gate.
When they emerged in the Heavens Arena, the calendar on the wall stared back at them.
Four days until Hisoka.