Akimine Mountain, Shells Town
“Kael, is this how you train Observation Haki?”
Gon rubbed the fresh, burning lump on his head and sucked in a sharp breath from the pain.
Kael lightly tapped the wooden staff against his palm and smiled.
“That’s right.
Haki is divided into three types: Observation Haki, Armament Haki, and Conqueror’s Haki.
The first two can be acquired through training, but only those possessing the qualities of a king can awaken Conqueror’s Haki.”
Kael’s ability, the Book of World Resonance, was rather unusual.
It could only create resonance after he formed a contract with someone and brought that person into another world.
While they remained in the Hunter world, he could not share Gon’s training gains.
Every world possessed its own unique system of laws, and Kael’s ability happened to bridge the differences between them.
Once a contract had been formed and the contractor entered another world, their body would become compatible with that world’s inhabitants, allowing them to cultivate powers such as Haki and Nen.
That was why Kael had brought Gon to this mountain to train in Observation Haki.
Observation Haki shared many similarities with En from the Hunter world.
Both could greatly enhance a person’s perception.
“Observation Haki is a sensory ability,” Kael explained.
“It allows you to sense danger even when you can’t see it, giving you enough time to evade.”
“We only have three days.
During that time, you need to learn how to avoid my basic attacks.”
Gon touched the lump on his head.
Thinking of his upcoming battle with Hisoka, determination returned to his eyes.
Kael blindfolded Gon and resumed their “special training.”
Every time the wooden staff struck Gon, the pain and insights Gon experienced were transmitted directly to Kael.
Training Gon was therefore no different from training himself—and Gon was the one who had to endure all the physical pain.
As a result, Kael swung the staff with an almost fanatical enthusiasm.
He showed absolutely no concern for the torment Gon was suffering.
Only extreme pressure could force someone to comprehend Observation Haki more quickly.
Gon’s talent was astonishing.
During the first hour, he could only rely on his instincts as a Hunter to dodge occasionally.
He was struck so many times that there was no point trying to count them.
Through their resonance, however, Kael could clearly sense Gon’s perception slowly spreading outward like a spiderweb.
Gon became increasingly sensitive to the flow of air and to killing intent—or, more precisely, the intention behind an attack.
Finally, after an unknown number of swings, another rush of wind approached Gon’s head.
His head instinctively tilted to the side.
The wooden staff brushed past his ear.
For the first time, Gon had completely avoided the attack.
Then came the second dodge.
The third.
It was as though he had finally learned to sense the trajectory of each attack.
He gradually became capable of effortlessly evading the ordinary strikes Kael had deliberately slowed down.
Through their resonance, Kael sensed Gon’s progress as well.
He immediately adjusted his attack speed, steadily increasing the difficulty of the training.
Inside their room at Heavens Arena
Killua cultivated his Nen while repeatedly glancing toward the place where Kael had activated his ability.
“Didn’t Kael say they’d return on the third day?”
Just as doubt began to rise in his mind, the space inside the room suddenly fluctuated.
A curtain of light slowly formed.
Kael and Gon stumbled out of it.
Kael’s face was deathly pale, clearly showing that he had exhausted a tremendous amount of energy.
Gon had several injuries, but his eyes were brighter than ever.
“Gon!”
Killua immediately rushed forward.
“What was that other world like?”
Another world.
It was a concept that normally existed only in novels, yet it had turned out to be real.
Killua’s curiosity had reached its peak.
“It was incredible!”
Gon spoke excitedly.
“They have power systems called Devil Fruits and Haki.
They’re different from our Nen, but they’re fundamentally quite similar.”
“Haki?
Devil Fruits?
Tell me everything!”
Killua’s eyes lit up.
He completely failed to notice Kael’s pale complexion.
Kael could only silently walk over to the sofa and begin restoring his depleted aura.
Closing his eyes and regulating his breathing, Kael discovered that although opening the passage had once again consumed an enormous amount of energy, his total aura reserves had noticeably increased.
It appeared that every time he opened a passage between worlds, it was equivalent to undergoing an extreme training session.
Each activation could increase his total amount of aura.
“So this is Observation Haki?”
Killua stood behind Gon and launched a probing attack.
As though he had grown eyes on the back of his head, Gon easily avoided it.
“That’s right.
It can sense your intention to attack.
Even without using your eyes, you can perceive an attack’s trajectory through the movement of the air,” Gon said proudly.
The corner of Killua’s mouth rose slightly.
His attack speed suddenly increased three- or fourfold.
Although Gon sensed the incoming blow, his body could not react quickly enough.
Killua’s fist sent him flying into the wall.
“Killua!”
Gon jumped back to his feet, covered his nose, and chased after him.
The two immediately began wrestling and causing a commotion.
Kael had wanted to recover in peace, but stray pillows repeatedly flew across the room and struck him.
After enduring it three or four times, he finally lost his patience and joined the battle.
By the time all three of them were exhausted and sprawled across the floor, Killua turned his head and looked seriously at Kael.
“Kael, I want to form a contract with you too.”
Kael looked at Killua without showing any surprise.
The desire to explore the unknown was part of human nature, especially for a boy like Killua.
“Really?”
A flash of delight appeared in Kael’s eyes.
After making the request, Killua had actually felt slightly uneasy.
He had been born into a family of assassins and possessed extremely sensitive nerves.
Furthermore, he had previously questioned Kael’s intentions.
However, the undisguised joy in Kael’s eyes swept away that small trace of anxiety like sunlight.
That wholehearted acceptance warmed Killua’s heart.
He nodded solemnly.
“Yeah.”
“That’s great.
You’ll be the third member of my pirate crew,” Kael said with a smile.
“Pirate crew?
Kael, you’re going to become a pirate?”
Killua was somewhat surprised.
“That’s right.
Pirates are extremely common in that other world, and many of them are genuine monsters.
From what I know, those monsters are concentrated in a place called the New World.”
“The New World?”
Killua curiously pressed him for more information.
“Yeah.
The four most powerful pirate forces there are known as the Four Emperors.”
Hearing Kael’s explanation, Killua immediately understood the situation.
He asked with a serious expression, “Are the Four Emperors strong?”
“Of course.
Every one of them possesses the qualities of a king, and three of the four are Devil Fruit users.”
“If we converted the quantity of their Haki into our aura measurements, each of them would probably possess more than a million units of aura.”
“More than a million?!
Those really are monsters…”
Killua’s pupils contracted slightly.
As a prodigy of the Zoldyck family, he understood the terrifying difference represented by that number far better than Gon did.
His shock only lasted for an instant.
His gaze immediately became sharp and grave as he rapidly analyzed the enormous gap between their strength and that of their future enemies.
Kael’s serious expression suddenly changed again.
With complete confidence, he declared, “But we’ll definitely surpass them.”
Killua looked at Kael’s confident smile and did not argue.
After all, Kael’s ability allowed him to share the results of their training.
Once their crew gained more members, the progress everyone made while training in another world would accumulate within Kael alone.
Kael was destined to grow stronger at an astonishing speed.
Surpassing those monsters was only a matter of time.
Killua was also extremely confident in his own talent.
Since he could cultivate Haki, he refused to believe that he would lose to the natives of that world.
“I’m already starting to look forward to it.”
“There are still fourteen days before Gon’s fight with Hisoka.
Shouldn’t we make another trip?
I want to train in Observation Haki too.”
Naturally, Killua had no intention of falling behind.
The way Gon had sensed his attack was completely different from Killua’s method of evading danger through pure assassin instinct.
“My ability has a three-day cooldown.
We’ll have to wait three more days before I can activate it again.”
Kael spoke with considerable helplessness.
“Kael, have you ever thought about buying a ship?”
Killua rubbed his chin excitedly.
Hearing this, Kael shook his head and gave a bitter smile.
“That would be difficult.
I can’t transport something as large as a ship.”
Just as Kael was feeling helpless, a particular person suddenly came to mind.
Owl of the Shadow Beasts.
His Nen ability, Fun Fun Cloth, could shrink enormous objects.
As long as Kael could find him, he could use Owl’s ability to shrink a technologically advanced ship they purchased and bring it into the world of One Piece.
There, it would undoubtedly become a creation far ahead of its time.
(End of Chapter)