The moment the battle ended, medical staff rushed onto the stage and carried the victorious Aoyama away.
By the time he was treated, most of his injuries were already healed, and his stamina had been restored to peak condition. While devouring the lavish meal provided by the Heavens Arena, he looked up at the man who appeared in the infirmary—Hisoka—and asked curiously:
"So… do you want me to learn Nen?"
Hisoka narrowed his eyes, idly playing with a deck of cards. He flicked out an Ace of Spades, spinning it elegantly between his fingers as he said:
"I can teach you, you know. I'll open your aura nodes, release all that hidden potential… With that much aura, you'll instantly become a formidable Nen user."
Nen.
Chakra.
At first glance, they seemed almost the same—both were born from the body. Nen was latent within, waiting to be drawn out, while chakra had to be refined. That difference alone split the two systems apart.
Ninjas pursued destructive power to its extreme—jutsu capable of shattering mountains with a single strike, manipulating Yin and Yang as well as the five elements, fusing them into entirely new abilities.
Dust Release, Lava Release… all products of fusion.
Shadow Possession Jutsu, the Sharingan—those were the pinnacle of Yin–Yang manipulation.
Nen, however, was different. Its focus lay in unlocking human potential. It was like the internal arts of another world: a true master of Nen could live far longer than ordinary men, even stand alone in a snowstorm and feel no cold at all.
In short, Nen was like a xianxia cultivation method condensed into the body—a path to power where a person could grow into something akin to a god.
By comparison, chakra offered only raw destructive force. Ninjas could indeed unleash techniques that seemed to destroy heaven and earth, but without the bloodline of the Ōtsutsuki, most were doomed to remain cannon fodder.
Aoyama smirked and asked with interest:
"You won't suddenly… You know, get carried away while teaching me and kill me on the spot, will you?"
Hisoka's lips curled into a playful grin. His half-lidded eyes suddenly widened with dangerous light.
"Who knows? An almost ripe fruit… It's hard for me to resist plucking it right away."
Compared to the shinobi world, the Hunter world's combat power didn't look as overwhelming at first. But anyone who truly understood Nen would come to respect its depth and strength. The legendary battle between Chairman Netero and the Ant King, for instance, was no less epic than Uchiha Madara's clash with the First Hokage.
Aoyama swung his legs off the bed and stood up, grinning broadly.
"That sounds interesting. If that's the case, then let's not waste any time. Let's start now."
Hisoka nodded.
"Fine. Follow me. I know just the place—a perfect spot for us to destroy as much as we want."
Because he had promised to take part in the Hunter Exam with Illumi, and because he was always searching for promising fruits to nurture—or to eventually hunt—Hisoka decided to give Aoyama a crash course in Nen. The very next day, they would head for the exam.
Aoyama, naturally, welcomed Hisoka's offer. It was his first time touching Nen—no slow exploration, no cautious trial-and-error. He needed his aura nodes opened in one go, all at once.
They arrived at an abandoned, wide-open plaza that had been unused for years. There, Hisoka forcibly opened Aoyama's aura nodes. The moment his aura erupted into the air, Hisoka's eyes widened in rare astonishment.
"I've never seen such a massive aura before… This is… ohhh, this is too exciting. I'm soaked already."
Aoyama's entire body blazed with life. His aura roared into the sky like a dragon. In sheer quantity alone, his aura surpassed everyone Hisoka had ever met—even those on his personal hit list.
Years of chakra refinement, daily taijutsu training, and the tempering of the Eight Gates—together they produced an ocean of aura, easily twice the amount of chakra in his body.
Hisoka regained his composure and explained:
"Focus your mind. Don't let your aura scatter. Keep it clinging to your nodes—you need to learn to open and close them at will. That's how you enter Zetsu, stopping any aura leakage."
"The more you waste, the more life you lose. If your aura drains completely, you die. Whether you can control it now depends entirely on you."
"The plane for the exam leaves in eight hours. Whether you can master Nen in that time… depends on your potential."
Hearing Hisoka's voice, Aoyama immediately understood what to do. Calmly, with confidence, he reined in the eruption. The wild torrent of aura, like a child with candy, obediently settled back into place.
His aura clung to his skin like a thin veil, warm and comfortable—like wearing silk, or soaking in a hot spring.
Aoyama closed his eyes, savoring the sensation.
"So warm… It feels like every bit of my potential is being drawn out. This is amazing."
Hisoka nodded approvingly.
"Of course. Nen is not as simple as you think. Now, since time is short, let's start from the basics—the Four Major Principles. First is…"
But just as Aoyama was concentrating, a strange phenomenon occurred. A book suddenly materialized out of thin air before the two of them. Its pages flipped open by themselves.
Aoyama blinked in confusion.
The Book of Monsters…? Why is it appearing here?
The open page glowed—the monster tied to his Akatsuki contract was illuminated, a shifting rainbow aura flowing across the parchment.
"What's going on…?"
Hisoka tilted his head, eyes gleaming.
"It seems I underestimated your potential. You've already manifested your ability. Judging from that… it looks like Conjuration, or maybe a Specialization-type ability."
To Hisoka, the "Book of Monsters" was simply Aoyama's Nen ability, which made sense. In the Hunter world, all strange powers were, in the end, related to Nen.
Aoyama didn't bother explaining. Instead, he quietly willed the book away. A faint voice brushed his mind—the voice of the monster itself.
Shaken for only a moment, he composed himself, dismissing the book entirely. Then he nodded at Hisoka.
"Let's continue. I need to master Nen's usage quickly. After all… I still owe you that fight."
Hisoka pressed a hand to his face, his shoulders trembling with laughter—a grotesque, almost demonic laugh that made the air itself chill.
"Yes… Yes, we do need to fight. Hahaha… This is wonderful. You're the perfect prey. Ahahahahaha!"
Watching Hisoka's madness, Aoyama couldn't help but think: No wonder he's ranked as one of the top ten freaks of all time. That pose, that twisted laugh… he is a total pervert.