Killua hummed upon entering the stands where spectators were spread about cheering loudly with a vibrant energy that she sort of liked. It wasn't as packed as she thought it would be considering the ridiculous line they had to wait in before entering. "It's been a while, but this place hasn't changed one bit."

Gon quickly turned his head to face the white-haired boy as they sat down, "Eh? Killua, you've been here before?"

"Yeah, when I was six," he continued, "My dad left me here without a penny. He said that I should reach the 200th floor before coming back home. It took two years."

Rukei always thought the Zakuya's training was pretty ridiculous but compared to being dropped in a fighter's den at the age of six, her training wasn't all that bad.

"If you want to fight people of Hisoka's level, we'll need to go higher. Let's hurry."

They both nodded when the intercom called over #1973 and #2055 to enter ring E. Gon set down his bag, exclaiming that he was starting to get nervous to which Killua gave him a two worded suggestion.

And if Gon's opponent-shaped crater left in the wall was anything to go by, it was a good suggestion to follow. Not too long afterwards, Rukei was called down too, her number being #2056. It irritated her that she was last, again, but she didn't make a comment on it lest Killua started being annoying about it.

"Any other words of advice, senpai?" Rukei joked lightly as she set her bag down, giving a side long glance towards Killua.

The boy thought about it for a minute before giving her a shrug, "You should just do what you always do."

What she always did? Rukei blinked in confusion before she gave a small smile in understanding. Her opponent was wary, as Gon just proved that the children in the arena were not to be taken lightly. But wary or not, her opponent was easily flipped over and knocked out, getting her a path to floor 50.

"The first 200 floors of Heaven's Arena are divided into classes, each compromised of ten floors," the elevator lady explained, "So after someone defeats an opponent in the 50s they advance to the 60s. If they lose, they'd drop back down to the 40s."

Gon listened earnestly, to which the lady seemed to be pleased with, "So that's how it works..."

"I've heard that after you pass the 100th floor, you get your own room!"

Rukei glanced behind her to see a young boy, a couple years younger than them in a white gi and red belt; she recognized him from earlier.

"Oh, I forgot to introduce myself. Osu*!" he started with a familiar martial arts greeting, "My name is Zushi! What about you guys?"

"I'm Killua."

"I'm Rukei."

"I'm Gon. Nice to meet you," the boy chimed, and they arrived at the 50th floor just a moment later. They stepped out of the elevator and Rukei gave a little nod to the lady as they went out. "I saw your fight earlier," Zushi mentioned, "That was really amazing!"

Killua glanced down at the boy as they headed for the counter, "What are you talking about? You made it up here with one match too."

The boy shook his head, "No, I still have a long way to go," he stated with a disciplined tone of voice, "By the way, what martial arts discipline do you practice? I study the Shingen-ryu fighting technique!" He announced, obviously quite proud of the technique he studied under.

"A school?" Killua repeated, "We don't have one, right?"

Gon shook his head and Rukei answered with a "Not really..." She wondered if the XX Alliance counted as a school, but she wasn't trained under a specific style there so she supposed not. It bothered her a little that she was given little bits of a bunch different fighting styles rather than one, like the Zakuya, but as long as she remembered everything she was taught, it wasn't a big deal.

"What?! You're that strong without training?" the boy hung his head low, "I'm kinda shocked. I still have a long way to go!"

And while the boy was firing himself up, light was applause from an individual coming from behind them, a tall man with glasses, "Zushi. You did well."

"Master!"

"You adhered to my teachings."

The boy nodded, well not really nodded, but gave a motion of the equivalent, "Osu! I am honored! Master, your shirt is untucked again."

He looked down to see that his student was right and sheepishly stuffed the fabric away. He was a bit disorganized as a martial arts master, which partly reminded her of her family. She really hoped the apartment would still be in repairable shape by the time she came back... "Ah, yes, sorry about that. Who are they?"

"Oh, these are Killua-san, Gon-san, and Rukei-san," Zushi introduced them to the man.

"Nice to meet you," the man greeted, "I am Wing."

There was a chorus of 'osu' and shift of stances* as they returned the greeting.

"I didn't expect meet other children," Wing noted, "Why are you here?"

Killua played spokesman for the group, "Uh... Well, we want to become stronger but we're also broke so we're making money simultaneously."

"Killua's a veteran here," Gon added informatively, or perhaps just to brag on the boy as he always did.

"I see...," he gave them a little bit of advice before they went on their way, "If you're up here you must be fairly skilled, but you should pay strict attention to the difference between your opponent's body and yours."

"Osu!"

"One hundred, fifty-two jenny..."

She opened up the envelop, dumping the coins into her palm. "Maybe enough to cover a drink."

There was a clatter of a can falling to the bottom of the vending machine almost as a response to her statement, "That's right," Killua affirmed, snapping the metallic tab back, "On the 1st floor, win or lose, your reward covers a canned drink. But beyond that a loss gets you nothing. A win over an opponent in the 50s nets you fifty thousand."

"That's a lot..."

But the veteran wasn't finished, "In the 100s, I think wins are worth a million."

A million? Gon and Zushi's faces accurately expressed her shock that she kept behind her steady gaze.

"Once you're past the 150s, you get ten million a pop."

"Ten million?!" Gon repeated, "Didn't you make it to floor 200 when you were here before? How much do you get for winning on the 200th floor?"

Killua paused and gave it some thought, "Well, I don't really know, because I quit once I reached 200. But when I was winning in the 190s, I had around two hundred million, total."

"T-two hundred..."

"And where's that money now?"

The white-haired boy laughed at them, as if they had said something ridiculous, "That was four years ago. Of course it's gone now. Spent it all on snacks!"

Gon turned stiffly towards Zushi, "Two hundred million on snacks, in four years?"

"What kind of snacks are these?"

Rukei gave Killua a blank stare that she was trying to express her disapproval which most definitely failed. Shichi would have been more vocal about it; while she was terribly disorganized, Shichi was strict on what Rukei ate and drank, even so far as to making the brunette keep a chart on her calcium intake.

Killua tossed away the empty can before advising them to head to the waiting room; as they all hadn't taken any damage, they were likely to be set up for another match. Somehow, she wished she hadn't as Killua and his big arrogant mouth gained many, angry, annoyed stares on them.

"#2054, Killua-sama."

She gave a glance towards the speaker in the room and back to the boy, "That was fast."

"#1963, Zushi-sama. Please head towards arena A on the 57th floor."

Rukei had a very strong temptation to scold Killua as he casually raised a hand to Zushi's display of good sportsmanship and brushed it off with a, "Sure. Well, you can't win them all. Better luck next time. I'll head out," he directed the last words towards the two of them.

"Yeah, good luck, you guys," Gon chimed encouragingly.

"Knock yourselves out," she stated, before following up, "Not literally."

Except they were going to knock each other out, or at least Killua was, but she was starting to think that it should apply for both as Killua insensitively told the two that he'd be waiting above.

"He really didn't have to be that blunt," Gon mumbled to which Rukei agreed with a huff.

-

When they asked about the match, Killua turned away with a "I ran into a little trouble."

"Then Zushi was pretty strong," Gon noted, as he fell into step with his friend.

"No, not at all," he shot down the idea, "He has potential. One day, he'll be strong. But right now, he's just target practice for me; his punches were weak. I was able to completely knock him around," the boy stopped suddenly, "But I couldn't defeat him."

Gon and Rukei glanced at each other at his statement. What was he talking about? He was on the same floor as them, wasn't he?

"I received the TKO from points, but I couldn't knock him out," Rukei's interest peaked at this. Someone the third testing gate opener Killua couldn't knock out? That was rare. "When he changed his stance, his aura reminded me of my brother's."

Interest turned into alarm at his statement, but Zushi hardly seemed threatening like Illumi at all, and the boy didn't have any kind of prior connection to Killua.

"I don't know what it was, but it felt dangerous. It must be some kind of technique," Killua finally turned to face them, "His master called it 'Ren.'"

"Ren," Rukei echoed. She heard the word somewhere before; it was said here and there in her workplace but it was often used in such odd statements that she had thought of it as some kind of codeword. Strangely enough, none of the files she sifted through contained the word.

Then people in the Alliance used the technique called Ren? But she had no memory of any of her co-workers training in Shingen-ryu. She also doubted Illumi studied Shingen-ryu, it didn't seem to be a very assassin like method.

They all sat down, and Gon turned to Killua curiously, asking for clarification, "So Zushi isn't supposed to use Ren until he reaches the top floor?" The boy didn't respond. "The strongest fighters are at the top, right?"

He finally lifted his head, a serious tone in his voice and look in his eyes, "Gon, Rukei, change in plans. I'm aiming to reach the top floor!"

She had flown all the way up to the 100s with her throw, she was actually surprised at the speed they were going at and the fact that they hadn't been pitted against each other yet. They were even provided a room so they wouldn't have to pay for lodging anymore; convenient and nice but Killua warned them on the upcoming opponents. But no warning was really necessary as they continued to climb steadily to the top.

They were moving along, having just obtained their prize money from their win on the 150th floor when Gon brought up the subject of a certain red belt from before, "Oh, that's right! I saw Zushi on the TV earlier."

"So did I," Killua followed up, "He's still in the 50s."

They all stopped simultaneously, as if they were all thinking the same thing, Gon being the first one to speak. "I wonder what that Ren you sensed could have been."

He hummed, "Maybe if we fight opponents higher up..."

"Why be so round about?" Rukei questioned with a sigh.

"Wouldn't it be faster to just to ask Zushi?"

Killua gave them a dry laugh.

-

"Ren is one of the four major principals. The four major principals for discipling your mind and body. Fundamental to every martial art!"

They all stared completely lost in the young boy's explanation as he continued on proudly.

"You must know Ten, learn Zetsu, achieve Ren, to reach Hatsu! This is all part of the Nen training!"

"Nen."

That was the word that Shichi had uttered over the phone before completely denying her little sister's request. Something that would get her closer to becoming a Hunter. She couldn't quite say anything because she was still organizing the words together in her head; if she blurted them out now she would be completely incomprehensible.

"Zushi," a stern voice called, footsteps following, she was surprised she could still understand what everyone was saying as her mind was very busy, "Are you sufficiently educated that you can teach others? Gon-kun, Killua-kun, Rukei-san*. There's an old saying that if you learn something piecemeal, you'll end up knowing less than you started."

"So a little knowledge is a dangerous thing?" Killua summed up, before going on, "But I want to know right now. Because it's related to the secret behind my brother's power."

Wing turned a bit more serious then, his voice lowering a little, "Your brother is able to use Nen?"

"I need to know what Nen and Ren even mean! I'll agree to the full learning process rather than a quick explanation!" He added, "If you're willing to teach me, I won't try to figure it out myself."

"Shichi-oneesan-" Rukei finally ended up saying, before realizing that she messed up even after she tried to make a script for herself. She cleared her throat when Wing turned his gaze on her, "My sister can use Nen, I'm sure, along with my affiliations." That word definitely didn't sound right for a twelve year old to use but 'co-workers' didn't sound normal either.

Wing gave in after a few moments of a stare down, "I understand. Come with me to my residence."

They waited as the sound of a squeaky marker drawing across a dry-erase board filled the room. A click of a cap snapping over the item signaled that he was finished, as Wing turned around, beginning his lecture.

"Now, listen carefully. Nen means to burn your own soul," he drew another character on the board, something very different than the Hunter writing, "In other words, it tests the strength of your will. And the four major principals are part of a training curriculum for strengthening your will."

It all sounded a pretty queer, suspicious even, as he continued on, drawing another foreign character on the board.

"Ten means to focus your soul into a single point to increase the awareness of your goals," he then pointed to the character underneath it, "Zetsu means to express yourself in words. Ren means to temper that will. And Hatsu means to act upon that will."

He then pointed to each of the characters in turn, encouraging them to repeat after him. She felt almost like a completely normal student, hardly anyone in the Alliance would teach her like this. Of course, the Zakuya was out of the question.

"Killua-kun, Zushi tempered his 'refusal to lose' during his fight with you. So allow me to demonstrate. Killua-kun," he called out, "I think I'm going to kill you now. Are you ready?"

Rukei took her previous thought back.

"Yeah, sure," he agreed casually, "It's not happening."

Wing was not the least bit bothered by the boy's arrogant tone, he seemed amused rather, "Let's take this step-by-step. First comes Ten," he shifted his stance, "I focus my soul into a single point. Zetsu. You can either express yourself verbally or mentally. 'I will kill you'."

There was a pause, and she wondered if anything was actually going to happen, until she felt something light but extremely unpleasant, familiar chill crawl across her. It didn't take longer than a second for the feeling to grow tremendously, almost the crawling turning to nearly crushing. Rukei took a step back as the feeling disappeared, being free to move again.

"That was Ren," Wing informed cooly to Killua who was practically clinging to the ceiling, as far away from Wing as possible, "If I temper my will enough, then I can act, Hatsu. If your will is strong enough, you can make your opponent back down, without moving a muscle. The concept of bluffing comes from this."

Killua dropped down from his position, far more cautious and wary than he was before, he had obviously underestimated the seemingly ordinary man in front of them.

"Ren hardens that which is soft and you lose the ability to correct and incorrect idea. Therefore, you should avoid using Ren until your soul has fully matured," the man warned them, "Right now, you and Zushi should be training your souls."

Killua didn't buy it, she could tell, as he turned on his heels with a "Let's go."

"If you wish to learn more about Nen, you should focus on mastering Ten. If you master Ten, you will no longer feel the pressure of an opponent's will."

"Thank you very much!" Gon hollered as he ran out of the teacher's residence while trying to catch up with Killua who appeared to be more or less, ticked off.

After they were distanced enough from the house, Killua spoke up. "Specs was lying."

"Lying?"

"Yeah. The explanation made perfect sense and Wing is clearly very strong," Killua admitted, "But his story had holes. Zushi's toughness," Killua clarified when Gon questioned, "He kept getting up after I knocked him down. I was getting irritated, so I... kinda didn't hold back on my last attack."

Rukei whipped her head to the side to face him, "What were you thinking?" She asked harshly; a serious punch from Killua meant force that could push back 16 tons, possibly more than that. A small child like Zushi taking all that on...

"I didn't mean to," he shot back with irritation, "But even then he still stood back up. No matter what level of willpower he has, that couldn't have kept him standing. He's hiding some other secret," Killua finished, before glancing back at her, "And so are you."

She gave him a confused, annoyed stare at the accusation before realizing what he meant, before she inhaled deeply relaying the full story of what happened with Shichi on the phone, "I've also heard the word being thrown around in the office. I agree with you about Wing," Rukei mentioned, "If Ten, Zetsu, Ren, and Hatsu mean what he really said, then their sentences make even less sense."

There was a hum from Gon, before he turned his eyes back on the towering edifice ahead of them. Whatever secret Wing had, they'd find it on the 200th floor.

。。。

This chapter has been split in half! The original 'Fighter's X Debut' is now also 'In Cold X Weather, Wear X a Coat'.