Wing gathered Gon, Killua, Zushi, and Sebastian in a quiet room, preparing to teach them about Nen. He started by explaining the basics of the six Nen categories: Enhancement, Emission, Manipulation, Conjuration, Transmutation, and Specialization.

"Now," said Wing, "I want you all to place a leaf on top of the water-filled glass in front of you. 

You will use your Nen to alter the leaf or water in some way. Based on what happens, we'll discover which Nen category you each belong to."

Gon took a deep breath and focused his energy on the glass. As he poured his aura into it, the water began to overflow. Wing smiled and announced that Gon belonged to the Enhancement category.

Next was Killua. He closed his eyes and concentrated on his aura before releasing it towards the water. Astonishingly, the previously tasteless water now had a sweet taste. Wing acknowledged that Killua was in the Transmutation category.

Zushi then attempted the same feat as his friends. Upon directing his aura towards the glass, 

Zushi managed to make the leaf gently move across the surface of the water without touching it. This act confirmed that Zushi was part of the Manipulation category.

Finally, it was Sebastian's turn. Mysteriously enough, he managed to do all three tasks: make water overflow like Gon's, make it taste sweet like Killua's and moved the leaf without touching it like Zushi's. Wing marveled at Sebastian's abilities and concluded that he possessed immense power.

Over the following weeks, Gon, Killua, and Zushi dedicated themselves to training under Wing's watchful eye while Sebastian spent most of his time observing Gon. At last, Gon felt confident enough in his skills to take on Hisoka.

With determination in his eyes, Gon approached Wing and announced he was ready to set a date for his fight against Hisoka. Wing listened carefully, then nodded in approval, congratulating Gon for his efforts. "Well done," said Wing, "You've passed the secret Hunter Exam. Continue to hone your skills, my students."
Gon's eyes widened with excitement as he pumped his fists in the air. "Really? That's awesome!" he exclaimed. "But what about my friends? Did any of them pass?"

Wing nodded. "Sebastian passed a long time ago, even though it may have seemed confusing for you at first. It's clear that you trust him as your butler," he explained. As for Kurapika and Hanzo, they've already passed as well. However, Pokkle is still struggling with mastering Ren, and Leorio is currently focusing on studying for his medical exam."

Gon looked at Wing curiously. "And why is learning Nen so important for being a Hunter? What does it have to do with fighting criminals?"

"Well, Gon," Wing replied, "Nen is a crucial part of becoming a strong Hunter. It empowers you with the ability to face off against dangerous criminals and protect the innocent. In fact, Netero - the head of our school of Nen - believes that mastering it is essential for all Hunters."

Turning towards Killua, Wing encouraged him, saying, "Killua, I believe you should take the Hunter Exam next year. You're more than qualified to become a Hunter."

Sebastian approached Killua and whispered into his ear, "You have to pass the exam, Killua. Trust me on this."

Hearing Sebastian's advice, Killua nodded determinedly and quietly promised himself that he would take and pass the Hunter Exam next year – there was no room for failure in his future.

Everyone celebrated Gon's success and prepared themselves for their next challenges as Hunters or aspiring Hunters alike – each determined to make their mark on the world and uphold the values of their chosen profession.

With newfound enthusiasm, the trio continued their Nen training under the guidance of their teacher Wing, seeking to grow stronger in preparation for future challenges. Sebastian, however powerful he may be, remained a silent observer of Gon's progress.

On July 10th, the long-awaited match between Gon and Hisoka finally took place. The stadium was packed with supporters for both fighters, their excitement resonating throughout the arena. As the crowd roared and waved flags, the two contenders stood ready in the center of the battlefield, their eyes locked on one another. On the sidelines, Sebastian impatiently watched, waiting for Gon to emerge victorious from his match.

With a burst of energy, Gon sprinted towards Hisoka, determined to land the first strike. 

However, Hisoka easily dodged and blocked every one of his relentless attacks without even taking a single step. Sweat poured from Gon's brow as he struggled to break through his adversary's defenses.

Hisoka couldn't help but smirk at Gon's futile efforts. "I haven't moved an inch since this fight started," he taunted with a devious grin.

Despite his mounting frustration, Gon's resolve only strengthened at Hisoka's boastful remark. In a display of power and agility that left the audience in awe, he grabbed a flagstone from the ground and hurled it towards Hisoka with all his might. The stone shattered upon impact, sending debris flying everywhere like a whirlwind.

Hisoka was momentarily taken aback by Gon's unorthodox move, but quickly regained composure and effortlessly punched away the storm of rubble. As dust clouded the air around him, a sudden silence fell over the battlefield.

Gon seized this opportunity to disappear from Hisoka's sight. Using blinding speed and cunning stealth, he managed to sneak up behind his unsuspecting opponent. With heart pounding in his ears and determination burning in his eyes, Gon drew back his fist and delivered a thundering punch straight to Hisoka's face.

The impact reverberated throughout the arena as Hisoka staggered backward – for the first time in their battle, he had been caught off guard. A deafening cheer erupted from the crowd as Gon finally proved himself to be a formidable foe against the arrogant Hisoka. Their fight had only just begun, and both warriors knew that they had a long way to go before a victor could be crowned. But for now, Gon's unyielding spirit had shown everyone that he was a force to be reckoned with.

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