- Born and Bred for the Best. -

It was safe to say that the Zoldycks definitely knew what they were doing.

There is a debate within the modern school of thought about whether your identity stems more from your "nature" – your genes and physiological makeup – or how you are "nurtured" – a product of your environment. Most scholars agree that there is some amount of balance of both aspects of your origins.

Additionally, the first years of your life are considered "formative years". When you are born, your mind, spirit, and personality are essentially a blank slate, and your experiences as you are raised serve as chisels on the smooth stone of your psyche. Over time, these influences solidify into semi-permanence, dictating your thought processes, opinions, values, tendencies, habits, and instincts.

Your childhood forms the foundation for who you will grow to become.

For Silva and Kikyo Zoldyck, this concept of the formative years, of nature and nurture, formed the core of their parenting approach. It was nothing new for Zoldyck patriarchs and matriarchs to train their children in their ancestral legacy, in the art of assassination. This tradition stretched back many generations and was so integrated in the family's philosophy that ignoring it was never even a consideration.

Rather, Silva and Kikyo were particularly ambitious. They had lofty goals for the future of the family trade, they knew that their genes happened to be compatible and vigorous, and they were the best in the world in their respective specialities – Silva in strength, speed, and power, and Kikyo in physical and mental stamina and durability. It was no question that their offspring were to be among the finest generation in the Zoldyck's long history.

Opportunities like this could not be wasted.

They began to train their first child, Illumi, at a very young age, as was customary. By the time a Zoldyck can walk, they have already mastered the Nine Tenants of the Senses. By the time they are three, their physical training has already made them capable of eliminating any average combatant. By age four, they will have already successfully completed their first assignment. It is this initial assassination that is considered a rite of passage – and their chosen methodology and style dictates what type of assassin they will become as they grow older and stronger. It is upon this achievement that they are granted a unique, secret middle name – one that is never spoken aloud by any family member in order to preserve the sacred power.

It is said that a Zoldyck who utters their own full name gains a blessing that amplifies their power one-hundred-fold.

Illumi,who utilized his natural talent at deception and his dexterity with needles to impersonate a target's beloved child and puncture their temple, was given the middle name of Piasu Kage – Pierced Shadow.

While their first child showed incredible potential, Kikyo and Silva knew that another was bound to be born – the future, pride and promise of the Zoldyck name. Family lore stated that this generation would give a white-haired king, third in the legacy marked by his father and grandfather, possessor of abilities that outstood the rest of his family – including his ancestors. It had been declared centuries back that this king would dominate the nations.

It was only a matter of time for this special child to arrive, and after their second child Milluki (Tensai – Genius), they had their answer.

The Heir was born on the stroke of midnight – coincidence or fate, who can tell? – with a shock of tell-tale silver hair marking him as a future Transmuter, and instantly-aware blue eyes. From the moment he arrived in the world, the newborn did not cry, but took in his surroundings with a silent concentration inconceivable for a minutes-old infant. His hands, rather than curled into the ordinary fists of any baby, were relaxed, stretching and pointing – already positioned to deal a killing blow.

From the moment their child proved to be exceptional, Silva and Kikyo met each other's gaze with a grin of mutual understanding. This was the one.

They named him accordingly – Killua – and unlike most Zoldyck children, his training began instantaneously. Not one hour after his birth, the pale newborn was brought outside and placed on the ground. A second passed, and a white rattlesnake bred for this purpose slithered forward. Killua had miraculously already rolled to his stomach, his head bearing unnatural strength as he met the snake's eyes. His hands splayed to balance himself as he engaged the approaching reptile in a staring contest.

The snake lashed out.

Venemous fangs sank into his shoulder, and the baby flinched at the pain, but did not cry out. Poison filled his veins, and he began to feel the effects as his newly-developed system was flooded with the killing poison.

But nature kicked in – his mother's genes already granting him with basic immunity to simple venom – and as he would continue to do for years in the future, Killua Zoldyck survived the first test.

From the day of his birth onwards, Killua received the highest level of training in Zoldyck tradition, reserved only for the heirs. Even so, his childhood was consistently oriented for one sole purpose: to reach perfection as an assassin.

Each of his family members contributed to his development from day one - his mother creating an unbreakable pain tolerance and iron fortitude, his father instructing him in combat, his brother Milluki instilling the values of an analytical mind, and his brother Illumi training him in each of the Zoldyck techniques.

(It was also in these early years that Illumi drilled into Killua an overall instinct of self-preservation, reinforced by the careful placement of a needle in his frontal lobe to restrain him and ensure his survival in the face of supreme threats. The heir could not - would not - be killed. He was too precious and valuable to fall prey to stronger forces.)

To be sure, Killua's nature was the product of a long line of masters in the craft of killing. All Zoldycks are born strong and develop quickly. His environment, however, was on an unprecedented level of focus.

And so, by the age of three, Killua was sent on his first assignment – the earliest any Zoldyck had ever been sent for the rite of passage. His family watched from the shadows as the toddler walked with a smooth grace generally seen in fully grown men, steady in his balance and methodical in his approach.

He unleashed chaos on his target and the target's entire household.

Dripping with the blood of his first kill, the white-haired heir turned to his family, surrounded by the bodies of ten victims, bladed fingertips still at his sides. Expressionless eyes dimmed with the controlling mental state created within the first few months of his life.

His mother gasped with joy, clasping her hands in pleasure, and reached out to stroke the young boy's head. His father crossed his arms and dipped his head in acknowledgment, and Killua relaxed, eyes closing.

He gained his middle name that day – Tome Raremasen. Unstoppable Army.

Early on, the child was a force to be reckoned with. When he turned six, his father sent him to the Heavens Arena with the direction to return only when he reached the 200th floor. Two years later, Killua returned to the mansion stronger than ever, and he quickly surpassed the rest of his siblings as the most gifted weapon in the family - even better than Illumi, though Killua did not realize this.

It was only a matter of time before the twelve-year-old destined king felt compelled to leave the household. His mother and Milluki attempted to halt his departure, yet he left the premises nevertheless under the impression that he wanted to reject his family's training.

However, Silva understood and made no move to stop the promised son. It was inevitable that Killua should leave, for he had completed the entirety of the training the Zoldycks could feasibly offer in the home. The greater world would build combat experience, add breadth to his skills…

And of course, he would need to develop Nen on his own.

Time away from the family would only help him to grow exponentially stronger.

And sure enough, it did.

Zoldyck eyes constantly followed him, however, watching over him from a distance, keeping tabs on his progress. His development inspired awe, surprise, and anticipation. Indeed, he was the strongest being this family had ever seen.

And when the time was right, they forced a reset with the touch of a button.

Time to come home, Killua. Time to attain your fated future. Time to begin.

- Phone Call. -

"He did what?!"

Gon winced and held the phone away from his ear with a sigh. He was still perched up high in this tree, with his hand holding the pressure against the still-bleeding wound in his chest, brow furrowed with confusion, frustration, pain, and fear. "You heard me right, Leorio. Killua… he's not himself."

"Where the **** is he, Gon? Get the **** away from him!"

Tired, Gon glanced out at the sunset on the horizon as he replied, "I don't know where he is. He moved so fast, stabbed me, dragged me out here, and vanished. He could be anywhere by now."

Across the line, he could hear Leorio slam things around while breathing heavily. "My flight leaves in about an hour, I'll meet you in a few days or so. Kurapika too - we need to regroup. Can't believe this… Once a killer, always a ****ing killer."

Gon frowned. "He's not."

"And someone who- what? Gon, you're not defending this freak, are you?"

"Killua is my friend. My very best friend. He's not a killer."

"Baka! A killer is someone who kills. Don't stick up for him - he murders people for money! He's good at it, it's his thing. Heck, he nearly killed you-"

"But he didn't." Gon closed his eyes, crossing his legs and leaning back into the crook of the tree.

"So? You lucked out. What are you saying?"

"I'm saying, Killua did not kill me," he stated calmly, quietly. "You said it yourself, he's good at killing, right? He's a professional-"

"Gon."

"-so if he goes for a kill he doesn't…. he doesn't miss. Not him. I'm still alive, though. That means he wasn't trying to kill me. Deep down, he-"

"Gon."

"Deep down, he's not a-"

"Gon, just… shut up! Okay? Shut up. You're just… I mean… ****" The sound of Leorio punching a wall prefaced his quiet hissing, "So you're saying that the fact he 'almost' killed you is proof that he's not a 'killer'? Are you really trying to sell me that, ya little moron?"

There was silence, as Gon said nothing. Leorio inhaled and groaned. "Figures. Killua could probably amputate both of your arms and legs and you'd still believe he's worth saving. Not surprising."

Gon shrugged to myself. "It's Killua, Leorio."

"... Right." There was a grunt, and then the med student said with a long-suffering sigh, "As always, have it your way. When the three of us meet up, we'll talk game plan for getting the little ****er back. You'd better watch yourself Gon." Leorio's voice was steady and confident as usual, but there was definitely a subtle tremble in his voice as he warned, "You always tend to see the good in people, yet you ignore the obvious. Even if Killua's not a killer at heart - which you'll never convince me of that, for what it's worth - he's still in a state of mind right now that won't discriminate. He's an assassin, and if nothing else, he's falling back on that training. He is ruthless, you can't deny that. He could kill you without a thought, and he wouldn't hesitate. So you shouldn't either. Basically… don't let him kill you. Got it?"

Gon swallowed, feeling a strange sensation weighing on his shoulders, and answered, "O-Okay."

"I'll bring Red-Eyes and meet you at the docks on Whale Island. Until then, don't do anything stupid, alright? That includes trying to track and 'save' Killua."

"Alright."

"You swear, Gon? Swear not to be a hero and get yourself murdered by the kid?"

"I swear, Leorio."

"Good. Take care."

The line clicked, and Gon put away his phone, debating whether to head back to Mito-san or stay up in the tree until the bleeding stopped. He didn't want her to freak out over a wound that ultimately wasn't going to be fatal. Plus - and he didn't tell Leorio this over the phone for obvious reasons - but Killua really did do a number on him. He wasn't one-hundred-percent sure he'd make it home if he tried moving at the moment.

So Gon gave Mito-san a call, leaving a message when she didn't pick up, and curled into a ball in the branches of the tree.

He wasn't really sure what he was supposed to be feeling at the moment, or what he was supposed to think. He know what he had to do, he knew that he needed to save Killua from whatever was driving him to these extremes, but other than that… maybe Gon was just confused.

So he put it out of mind and closed his eyes, succumbing to restorative slumber. When he woke up, he should be recovered enough to return to the house, let Mito-san know what's going on, and think of next steps to find his best friend.

Hang on, Killua. I'm coming for you.

- Raw Innocence. -

Killua walked away from the bedrooms where three more victims lay dead in their beds. Mother, father, five-year-old daughter. Child's play.

Mentally, he tallied up his progress so far. Let's see… Killua took another lick of the popsicle he swiped from their freezer and hummed thoughtfully, dropping out the window to the street below. Twelve, carry the one... Ah. Eight hundred ninety-seven.

Well, that just left a little over a hundred to go. He was in the home stretch. Another lick of the popsicle.

That nagging feeling in his head prodded him again, and he carefully did a 360 to scan his surroundings once again. No tails. Just as he thought. Paranoia struck again, both a blessing and a curse. Killua shrugged and pulled up the Index on his phone, clicking the screen to check off Lydia, Rachel, and Vernon Tuso before scrolling to the next set of targets. An individual, and then a family of five. Got it. He ate the rest of the popsicle and toss the stick in the trash, pumping his fists when it made it in. Two points.

Okay.

On to the next city.