Illumi stared at the man before him.
He had come tonight on his father's orders. Originally, he could have chosen a peaceful daytime meeting. That was likely what the family elders expected.
However, after witnessing the "intimate" exchange between Kevin and Killua, an inexplicable irritation had taken root in his heart. Thus, he'd ultimately chosen this method of infiltration—a meeting that reeked of ill intent.
He had observed Kevin before. While it had been incidental to keeping an eye on Killua, he was supremely confident in his observational skills. In his assessment, while Kevin's physical conditioning wasn't weak, it still fell considerably short of the bodies forged by the Zoldyck Family's training from infancy. Had Kevin not mastered Nen, he probably couldn't even defeat Killua.
Since Kevin had remained active below the 200th floor, his Nen usually maintained only the most basic Ten. Although he mimicked an ordinary person's dissipating aura, careful observation could still reveal the energy wasn't truly scattering. Unless one engaged him in close combat, like Kite had, it was easy to be fooled by this facade.
Illumi truly hadn't expected what came next.
The moment his En enveloped Kevin, the other man was instantly alert. It wasn't uncommon to detect probing En, but the issue was that Kevin had been in deep sleep. Typically, only those who had undergone specialized alertness training could maintain such sharp reflexes while unconscious. This was inconsistent with his previous observations.
And the subsequent battle had been even more unexpected. The explosive, aggressive Nen Kevin displayed was utterly at odds with his external impression.
As Illumi silently analyzed, Kevin's aura erupted once more. A potion vial materialized in his hand, and he raised it to his mouth as if to drink.
Seeing the inexplicable surge of power, Illumi made a snap decision.
"I surrender," he announced, his voice flat and devoid of inflection. He slowly raised both hands.
Kevin was momentarily stunned, but the potion was already down his throat. His aura burst forth with renewed intensity, and he shot toward Illumi at an even greater speed. A massive concentration of aura poured into his right fist, making the incoming blow exponentially more lethal.
"Only when you're on the ground will I consider that a surrender."
So fast.
Even faster than before.
Illumi, who had initially tried to dodge, instantly knew it was too late. What technique is this? A sudden burst of aura exceeding his visible output? A Nen ability? Or deliberate concealment?
With no other choice, he gathered his own aura into his arms and braced for the impact.
CRUNCH!
A sound of shattering force echoed. Illumi was launched backward like a broken kite, crashing heavily into a shop's support pillar. After skidding another meter, he didn't remain down. He scrambled from the rubble and leaped fiercely onto a nearby utility pole. Mid-jump, he flung out several Nen needles.
The needles successfully stalled Kevin's follow-up attack; Kevin had no choice but to halt and bat them away with aura-infused slaps. He couldn't afford to be hit. A single needle could mean control, and his hard-won advantage would vanish instantly.
Illumi stood on the utility pole, backlit by the moon, and glanced dispassionately at his left arm. It was bent at an unnatural angle, swollen and undoubtedly fractured. His expression didn't change.
He had no intention of continuing this fruitless battle. The cost-benefit analysis was clear.
"I am Killua's older brother," he stated.
Kevin truly stopped then. He remained in a guarded stance, watching the man and the needle still held in his functional hand. The techniques and the feeling of the earlier fight did bear a resemblance to Killua's style, though their appearances—even their hair color—shared no similarity.
"If you're Killua's brother, then why…"
"It is a warning," Illumi replied in his emotionless monotone. "Do not teach Killua Nen. This is a warning from the Zoldyck Family." As he spoke, he retracted the malevolent-looking Nen needle.
Hearing this, Kevin found himself inclined to believe it. "Since it's a request from Killua's family, I naturally have no reason to disregard it." He agreed readily; in truth, he'd never had any intention of teaching Killua Nen in the first place.
Even if Killua seemed eager to learn through indirect means, he was still far too young—only seven. With the misunderstanding resolved, there was no need to continue the fight. Kevin wasn't the type to seek out conflict for its own sake.
Maintaining his vigilance, he increased the distance between them further. "I hope you'll change your habit of loitering outside people's windows at night in the future," he said, his tone polite but firm. "I have plenty of free time during the day. Normal visits are welcome."
It was both a warning and a dismissal. Then, he pulled a small potion vial from a pouch at his waist and tossed it over.
With a fluid, practiced motion, Illumi intercepted it using two of his Nen needles, pinching the vial between them. His gaze remained calm and inscrutable as he stared at Kevin.
"Consider it compensation for your medical expenses," Kevin offered.
Illumi's hand, the one holding the vial, tightened almost imperceptibly. He rarely experienced emotional fluctuations regarding anyone other than his targets. This time, it was distinctly negative. Yet, the emotion didn't dictate his actions. With his other hand, he produced a card and flicked it toward Kevin.
Kevin casually picked up a loose piece of rubble and deflected it, catching the card embedded in the stone. Before he could ask, Illumi spoke.
"If you have an assassination contract, call that number."
In Illumi's world, personal matters and business were strictly separate. This man seemed like a potential future client.
"Tsk, what kind of situation is this?" Kevin muttered under his breath. He'd just finished a brawl, and now the other guy was handing out business cards. What normal person needed assassination services?
After delivering his message, Illumi turned and left, melting into the shadows without a sound.
A pity, Kevin thought. He didn't drink the potion on the spot. He'd been curious to observe the side effects firsthand.
He didn't discard the card, however. He tucked it away quietly. One never knew when such a contact might prove useful.
The battle had ended abruptly. By the time nearby residents, awakened by the sounds of destruction, rushed to the scene, all they found was a large crater in the street and a badly damaged support pillar on a nearby shop.
The next day. A rented training hall.
Killla was launching a frenzied assault on Kevin, who merely defended and occasionally sidestepped. Whenever Killua left an opening that was too obvious, Kevin would deliver a sharp palm strike, sending the boy tumbling across the mats.
"Try a different attack pattern. I've already learned this one," Kevin suggested.
Killua, sprawled on the ground and panting heavily, seemed to have no intention of getting up for another round.
"Tired? Take a break, then."
As soon as Kevin sat down, Killua scrambled over and plopped down beside him. He fixed Kevin with wide, pitiful-looking eyes.
"What do you want?" Kevin asked, already sensing the direction.
"Hehe," Killua giggled, his expression shifting to one of pure, mischievous curiosity. "That aura you used before… what was that?"
As expected. Kevin sighed inwardly. "Didn't you say your brother knows it too? Why don't you ask him?"
"Ha!? That guy? I don't want to ask him for anything." Killua's face openly twisted with disgust, and he waved a dismissive hand.
'That guy'? So Killua and his older brother weren't on good terms. Interesting, considering how concerned Illumi had seemed.
"Since someone in your family knows it, but you're unwilling to ask… then I naturally can't tell you either."
"Tsk. How boring." Killua pouted, looking genuinely unhappy, but he didn't press further. He'd seemingly been prepared for this answer. "I'm tired. Let's stop here for today." With that, he got up and stomped out in a huff.
Kevin simply smiled, watching him go. He wasn't worried. He knew Killua would be back tomorrow.
In truth, Killua had never really expected to get a straight answer from Kevin. His hope, much like Kevin's own method, was to observe and learn through combat—to steal the technique through sheer mimicry and repetition, just as Kevin had done to him.