Hey this idea was stuck in my head for quite a while now, so I decided to put it into a story. If you see any mistakes be sure to tell.

(Warning: While Illuto is the main character for this story, he does not have main character syndrome. So he is not that of a main character material and I don't plan to make him like that. This is simply a story of an Oc. So he is like a main character in this story, but a side character from Canon.)

I do not own Hunter x Hunter or the picture, but I do own my ideas and OC.

Enjoy!

"Rena, please give the answer for question four." The math teacher spoke.

"Hmm...5.3?" I hesitantly answered.

Then the teacher sighed, "That's correct, but next time pay attention to class rather than daydreaming."

Laughing at being caught red-handed I replied, "Ok."

I refocused my attention to the board, but to be bored after ten minutes of staring at numbers. I let out a yawn at the sleepy atmosphere of the classroom, ready to fall asleep at any moment.

'Ring~!' The bell had rung and many stood up heading to the direction of the exit.

I myself also packed my bag and slip it on my shoulders, going with the flow of the crowd to the front door I had my attention on my phone not paying attention to my surround at all.

Walking down the stairs I checked the latest updated mangas and clicked on Hunter X Hunter.

It seems like the author finally went out of hiatus. I had read it when a long time ago so my memories of it is kind of fuzzy. I just downloaded the chapters this morning so I just need to re-read it.

"Watch out!" I heard someone scream in my direction. The boxes of a female teacher fell to my direction, I stumbled then descended from a high spot.

I fell head straight to the ground.

When the floor made contact with my head I had lost my conscious.

Everything faded to black.

Newborn

"He's so beautiful..." A woman's voice spoke as she held a small bundle in her arms.

The man with blond-white hair grunted at his wife and stared at his firstborn, "He will grow up strong, to be the next head of the Zoldyck family."

"What will we name him, Silva?" The wife of Silva's asked.

The current head of the Zoldyck family thought for a moment then smiled. He brought his hand and pet the short white hair on his son's head.

"He would be named Illuto, Illuto Zoldyck," Silva answered his wife.

The small bundle of joy shifted and scrunched up his face, awoken by the conversation between the pair of the new parents.

Kikyo admired her son's features. He has white hair just like his father and the same nose as her's. Illuto gave a big yawn and opened his eyes, the colouring of his eyes are like her own eyes, Black.

'Where am I?' Rena thought to herself as she observed her surrounding.

She was in the hallway one moment then suddenly when she woke up she was in this luxurious bedroom.

"Illuto, you finally woke up." The unfamiliar woman said.

'Illuto? Who is that?' Rena thought.

Rena tried looking around and spotted a man beside the bed. They both looked oddly familiar, but she couldn't get a grip of who they were.

"Silva, please inform father of Illuto's birth." The woman spoke to the tall man.

The white-blond haired man gave a 'Un' as an answer and left the room. Rena's attention was focused on the man heading to the exit then it struck her.

'Silva! That's Killua's father, that means the woman holding me is Kikyo.' Rena is now shocked by the realisation. 'Am I in Hunter X Hunter world now? But as I remember there is no Illuto in the story.'

"What's wrong Illuto? Mama is here." Kikyo cooed at her.

'Is she calling me Illuto? Am I Illuto? But if I'm here as their child wouldn't that mess up the story?'

It was not long when Silva returned with an elderly man by his side. Rena recognised his appearance and could instantly identify him as Zeno, he had his hands behind his back and his body hunched forward.

"Is that Illuto?" Zeno asked the couple.

"Yes, father."

Zeno's gaze landed on his grandson's face. It seems like he had inherited the Zoldyck's white hair, but the thing couldn't be said for his eyes. While himself and Silva had pale eyes, Illuto certainly has dark eyes like his mother.

"Silva, Illuto as the firstborn will have to be burden with immense training, I want you to start feeding him weak poison once he reaches one year old," Zeno instructed his son.

"I understand," Silva said.

6 months old

Now that Rena from the other world became Illuto from the Hunter world, she now he has a lot of time (an advantage of being a baby) to plan and decide what he would do.

The sudden change of gender certainly did gave him a shock, but he wouldn't mind at all because he acted more of a tomboy in Rena's life

Would he want to return to Rena's life?

No... there is no significance in that life.

Rena's parents divorced and had married others, she had to move houses many times and her friends constantly change. She constantly drowns herself to the internet to get through the depressing nights.

He did not have any reasons to go back.

At least in this life, this family cared for each other, well, kind of in a messed up way. But at least people cared.

When he overheard he was the first born and apparent heir to the Zoldyck family, he went into a frenzy where he fried his brain, 'Wasn't Illumi the firstborn!? Why am I the heir!?'

After calming himself down he calmly assesses the situation, Illumi was first born and he wasn't the heir. Then there must be a possibility where he will not be heir after all.

It had been mentioned many time in the story that Killua was a prodigy so it's no big deal. It's not like he would get attached with being the heir.

Though what really worried him was his existence in the story.

The temporary hair worried if his appearance in the story would cause a butterfly effect. Surely Illuto's appearance in the Hunter world should not be that drastic of a change, there will be slight alterations but it should not a problem.

He vows to not change the plot dramatically.

Since it's not in his personality to meddle with something that is not his business.

"Illuto!" His mother barged into his nursery room.

He was snapped out of his thoughts and stared at his mother, who wore an oddly happy expression.

"You're going to be a big brother!" Kikyo announced.

Ah.

Illumi is already on his way.

1 year old

Illuto had a few odd developments in his life lately.

When they start to feed him solid foods (gooey mush) he has gotten sick for a few days and the food tasted a little off. Then he remembered when he was a newborn, Zeno mentioning feeding him poison.

To build up his immune to poison, he was stuck in bed feverish for a week. Finally, the fever settled and his small body slowly adapts to the foreign poison in his system.

He really wanted to sue his grandfather.

'Who willingly feeds their children poison!?'

Well, apparently this family of assassins.

The butlers who took care of Illuto, they first noted Illuto-sama was a quiet baby when they fed him food he would pull a face of a grimace. While that is hilarious, it is unprofessional for them to giggle at the heir.

Illuto thought if the food is bad enough, then his mother is on a whole new level.

His mother would visit him most of the days, while his father would drop in once a while. While she is not as annoying depicted in the show, those hugs of her's should be toned down a bit for the sake of his back and maybe the high pitched squeals.

Kikyo tried standing him on his two legs and watch him attempted to walk for the first time. At first, he had support from his pregnant mother, but once she let go of her hands he plopped to the ground.

"How cute!" Illuto mother squealed and her electronic visor undoubtedly recording the event.

"Illuto-chan! Come to Okaa-chan!" Kikyo cheered for her young boy.

The temporary heir would love to give an annoyed grunt to his mother's voice but decided against it.

He reluctantly used his arms to push himself up and stumbled to his mother. Kikyo held her arms out and caught him once he reached her. She gave her son a huge hug for the first steps in his life.

Kikyo was a normal (not so normal) mother. She wouldn't screech or have that over possessive tendencies yet like shown in the show. Illuto predicts, once Killua is born, the ear-killing screech shall occur. He should prepare for his ears to get blown off.

1 year 6 month old

When Illumi was born, he couldn't see the cute baby as the psychotic (brother complex) man he would grow up to be. Illumi was innocent and undoubtedly the shimmer in his eyes will undoubtedly disappear soon as he entered the family business.

"Otou-san, what's his name?" Illuto asked his father, though he already knew the answer.

"Illumi." The white-haired man replied to his son.

"I see...Illumi." The mistress tested the name on her tongue.

And thus the welcoming of Illumi to the world was shortly celebrated by the trio. Soon after, Silva had to return to his quarters to prepare for his next job. Which left the white haired boy to accompany his mother.

"He's so small…" He said to no one particular.

Illuto never had the exposure of being an older sibling, no one had told him the feeling of protectiveness towards the small newborn is this great.

He hears his mother giggled, in which he lifted his head up.

"Promise me that you're going to be the best brother." His mother gently spoke while petting his head.

That is when Kikyo had said those words, Illuto realised, they aren't just fictional characters.

He is not living in a fake world.

They are not people in a show where he would watch as a child. All this time he had regarded them as unimportant.

They are real living people.

This is his world now.

And they are family.

"I promise." He said with a clear devotion to looking after his brothers.

In the future, many of Killua's difficulty was caused by the small baby sleeping so peacefully in his mother's arms.

It's distressing to comprehend the outcomes of his younger brothers.

You know the vow where he wouldn't want to meddle with the main affairs, screw that.

He vows to look after his brothers and family.

But sadly Zeno was not present as he was requested from a job he could not deny, the pay was handsome so he had to skip out on the birth of his second grandson.

But regardless, Illuto would frequently visit his younger brother. Watching by the crib that used to be his, he caressed the cheeks of Illumi's and wondered if he could stay small forever.

'Maaaan, there is so much family drama in the future. What a drag!' Illuto thought to himself.

2 years old

Illuto was bored.

He was playing with Illumi, but his brother needed to nap and he was left with nothing to do. He wandered around the mansion aimlessly with his now longer hair swaying as he walked.

He was left to ponder, having to notice the difference of treatment between himself and his little brother.

Illumi did not receive the same love as Illuto did. Kikyo's love was more towards her first child and Silva was slowly appearing less, which did not help. No wonder the dynamic of the Zoldycks was messed up. Isolation and favouritism had caused many of the unique personalities.

Zeno was heading back to his quarters. But noticing his eldest grandson wandering, he observed the expression on Illuto's face. The blank emotion did not help with his observation, so he decided to approach him.

"Illuto, you have some time?" Zeno informed Illuto of his presence when he spoke.

The heir turned around to the voice that belonged to his grandfather.

"It seems like both of us have nothing to do. Would you want to follow me to play a game of Shogi?" Zeno questioned.

"I would love to, Ojiisan," Illuto replied following his grandfather.

'I had played Shogi before, but my memories are quite fuzzy.' The younger heir tried browsing Rena's collection of memories, to see if he still remembers.

Zeno is no fool when he observed his oldest grandchild. Underneath the polite mask he had worn, he could tell Illuto is a genius no matter what anyone tells him. Illuto did not hide his intelligence, it is more of he never mentioned it; smart kid.

Many would assume at first glance Illuto's intelligence if of a child, but the mental capacity of that child is beyond a two years old.

Zeno arrived at his room and pulled out a wooden Shogi board and set it on the table. He carefully explained the rules to the white-haired boy, amused when the boy soaked all the information of the rules. If this turns out right, Zeno could estimate the approximate mental intelligence Illuto holds.

"Please, let us have a good game." Zeno bowed to his opponent.

Illuto bowed back as a courtesy to be polite.

Then the game began, Zeno took his Rook and moved it up. With a calculated stare, he watched his heir's hand also picking up a Rook and moved it up.

With the time passing by the game started to meet the end of the round, Illuto had been cornered by his grandfather many times and he barely even see the point where the trap was laid for him. With his King trapped by the Rook and Gold General, he couldn't move his King to a safe spot.

"Checkmate." His grandfather spoke.

"Ojiisan, that was a great match," Illuto said, admiring his grandfather's skill in Shogi.

"You had a chance to trap my King a few moves ago, but why didn't you? The game will not progress further and you would have become the winner." Zeno's eyes made contact with the black eyes.

"Huh?" Illuto dumbfounded by the news.

Zeno gave a sigh, but he founded what he wanted. Illuto is certainly a smart boy if with time he would have been better in the game. Considering this is the first time he played the game. While he is indeed a genius; the match had gone for 20 minutes, Zeno is impressed with how the game progressed.

"You could have cornered my King from a few moves before I moved my Gold General in your direction," Zeno informed his grandchild.

"Hmm." Illuto looked at the board again to see the position of the wooden pieces. "Ah!" He now can see the time when the left side was weakened due to his grandfather's General ascending to his King.

"I see, I did not realise that." Illuto felt disappointed with the new information.

The grandfather of the heir studied the small boy. With the correct training, the young heir could be considered a monster in both physically and mentally. He liked to see the outcome if he personally trains the heir.

"Ojiisan, would you mind for another round?" Illuto questioned.

"I wouldn't mind at all," Zeno responded.

3 years old

Illuto is considering that God hates him.

Just after his third birthday, he was ready for training and homeschooling.

And man, the training was brutal considering that Zeno was the one directing his routine. First thing in the morning he was stretching his body in weird positions, apparently to build flexibility. But screw that, his pelvis is aching so much. He wasn't a very flexible person in Rena's life and bending his legs one-eighty to do a split, he first flinched at the idea.

He then has to run around the mansion with weights after having his pelvis damaged by the previous activity. And don't forget when Zeno threw balls at his legs to train his reflexes, he would trip when he was too slow to dodge the ball.

But the homeschooling was a breeze for him, considering being a teenager in his previous life.

The time when he has breaks are lunch, dinner and time to head to bed.

Now with a packed schedule, the temporary heir had no time for his younger brother. With only limited time of dropping in every day, Illuto tried making the best out of it.

Illumi is now 2 years old with the exposure to only his immediate family and servants he would tend to get bored. Without his older brother visiting him more often, he would have nothing to do. But when his brother was in training his mother would come to his room.

Not to mention when Kikyo was in a need of dressing up her two sons as girls, always wanting girls she had to result using her boys to satisfy her needs. Illuto wouldn't mind having to cross-dress, being a girl in Rena's life.

But even being a male, he was prettier than her previous life! How unfair!

"Illuto, Illumi. Some time in your career you would need to disguise and fool your target, so remember the correct way to put on a dress." Their mother instructed them.

Illuto loved this Kikyo compared to post Killua's Kikyo. She was their mother while she wasn't the best one in the world, she filled the role of the mother very well. Just a few more years till Killua is born. Illuto would make the best of the current Kikyo as much as he could, he hoped he could tone the annoyance down for his brothers.

4 years old

Throughout the year Zeno upped the training routine. He threw Illuto into the electricity room, which was designed to torture but it was an exception for family members in training. The young heir wished that Killua would be born sooner so he wouldn't have to bear the brutal training. But as time gone by, he had now gotten accustomed to the training.

It was also at the same time where Illumi was beginning his own training, supervised by Silva.

"Ne, Ojiisan." Illuto moved his pawn.

"Yeah?" The grandfather of the temporary heir moved his Rook and looked up from the board.

"If there was a person with more potential than me in this family, would that person be the heir?" Illuto dropped the bomb while having Killua in his mind. That was a question he waited 4 years to ask.

Zeno calmly assessed his grandchild when he moved the Lances.

"If you're talking about Illumi having more potential than you, then yes, he would be the heir." His grandfather confirmed whilst moving his Bishop. "But that would be highly unlikely, my training is different to Silva's and I am training you to become the successor."

"But what if a younger sibling was born and possess more potential?" Illuto asked countering the Knight with his Gold General.

"Why you ask? Worried about your position being stolen?" Zeno smirked at the young child.

The heir broke his concentration from the board and gave a rare genuine smile, "No, I wouldn't mind at all."

"But whatever you ask, you are the current heir, you are expected to carry on the family's tradition until if a new successor is born." His grandfather responded. Surprised slightly when Illuto broke his mask with the smile.

The game progressed with the sound of wooden pieces tapping the board, "Checkmate." Zeno once again became the winner of the round.

The match had now lasted for around one hour now. Zeno is pleased with the tactics Illuto came up with and the general improvement of the game. Soon he would have a great opponent to play against.

Illuto looked at the clock on the wall and noticed it was night time, he got up stretching his legs. They had played for a long time and now it's almost for him to return to his room.

"Goodnight Ojiisan, I will see you tomorrow morning." Illuto headed to the exit.

Just as he opened the huge doors, his grandfather stopped him in his tracks.

Zeno closed his eyes and said, "Remember Illuto, you are the current heir and I expect the best out of you."

"Of course." He left the room

5 years old.

Blood.

The blood stained his hands.

He couldn't stay here anymore longer or else he would be caught by the security.

Illuto was sent to his first assassin mission, to assassinate the leader of an opposing mafia boss of his client.

He couldn't understand the feeling he was experiencing. He was brought up as a ruthless assassin in this life. But the memories of Rena had made him feel remorse for killing the man.

He silently slipped in the darkness of the alleyway and sensed a presence behind him.

"Good work." The voice of his grandfather illuminated the alley.

His grandfather was watching him doing his work, then he just saw that he hesitated for one second.

"You yourself know that assassin's don't hesitate. It's understandable for your first mission but if that happens in your next, it could cost your life. You must cast away your emotions during the missions." Zeno informed.

"I understand."

"Now you have finished the first mission I could finally teach you Nen," Zeno said.

"Nen?" Illuto asked.

He once wondered if it's okay to practice on his own to learn Nen, he did meditate and saw the white aura floating around. Without proper guidance he would have a hard time truly master the properties of Nen, so he waited for his grandfather to mention something about it.

You would say he waited like a fool to learn Nen, but if he did mention it to Zeno it would raise suspicion. Illuto can be a very patient boy, he is always patient in this life to wait for the story to progress to the main canon. So waiting is no problem for him.

Zeno took the question as if he didn't know what Nen was. "Yes. Now let's head back."

They both took an airship back to Kukuroo mountain, the trip was drowned in a comfortable silence where Illuto would clean his hands with wet wipes and the knife he used on the mission.

They had arrived at the testing gates of the front garden of the Zoldyck.

When Illuto first left the mansion for the first time he didn't consider the gate to be this big but seeing it in real life certainly beat the ones shown in the manga (anime).

Illuto and Zeno were greeted by the guard by the gates as they walked to the gate.

His grandfather went first and easily pushed all the seven doors. Illuto watched his grandfather walk in, he waited patiently for the doors to close then proceeded to get ready to push the doors. He used his two arms and got it open to the third door.

Wasn't that the same weight Killua could push when he was twelve.

The two Zoldyck walk up the forest and arrive at the inner gates of the mansion. A butler was stationed there greeted them and stepped aside, letting them pass through.

"What I am going to teach you is a technique that allows a living being to use and manipulate their own life energy," Zeno informed. "It is constantly surrounding any living being and you would have to meditate to control the flow of Nen."

"Ah, I see. So that is what it's called." Illuto kept up his lying facade. "This white flow is called Nen."

Zeno doesn't seem surprised at all. "It seems you already know about, then I could pick up the speed with your Nen training."

Illuto wants to cry, his big mouth shouldn't have said that.

He was told to follow Zeno to the training room. A butler was ordered to get a glass full of water and a leaf.

"I want you to put your hands by the glass and concentrate on your Nen." Illuto's grandfather instructed.

He did just that, but nothing happened to the water, "Try tasting it."

The heir dipped his pinkie in the water and tasted briny saltwater, scrunching his face in disgust he turned to the chuckling elder.

"You're a Transmuter, just like myself and your father. This makes it easier to teach you. Transmutation allows your aura to mimic properties of a substance." Zeno said. "To start off with, your main task for the week is to decide on a property, once you decided on which one we can work from there. But, alongside I shall teach you the four major principles of Nen."

"I understand."

'Hmm, what should I do?' Illuto thought as he flipped the textbooks, hoping he could find something to base his Nen off from.

He was flipping aimlessly, then something caught his attention.

The science behind Shadows:

A shadow is a dark area where light from a light source is blocked by an opaque object. It occupies all of the three-dimensional volumes behind an object with light in front of it. The cross section of a shadow is a two-dimensional silhouette or a reverse projection of the object blocking the light.

'Oh! I could use this!'

"Knock, knock" The noise came from the door.

"Yes?" Illuto questioned.

"It's me, Illuto-niisan." Illumi's voice came from behind the door.

"Come in." The white hair responded.

The door opened to a small boy of four years old. Illumi did not have his signature long hair yet, but the eyes of the child had already lost their innocents.

"What's wrong?" The older of the two asked.

"Mother has been bothering me more now that she is carrying a child," Illumi stated.

Illuto could empathise with Illumi. But currently, as the heir he is training with his grandfather, Kikyo did not often bother him. The same couldn't be the same for Illumi though.

"Do you just want a breather from mother?" The white hair asked.

"Yeah." The younger answered.

Illuto chuckled, "That is understandable, but in half an hour I would have to meet up with Ojiisan. So you would only have limited time away from Mother."

"That's fine." That is enough time to catch up with his older brother.

6 years old

Today is a rare day where Illuto has a break from training and work.

"Illuto-niisan, is mother going to be okay?" The five years old Illumi asked after hearing the screams of his mother.

Illuto looks down at his younger brother and smiled, "Mother will be fine, she is birthing our little brother. Remember Illumi, a big brother's duty is to protect our younger siblings and well, of course, our family."

"A big brother..." Illumi whispered.

The screams suddenly ceased and the cry of a baby illuminated the hallway.

Silva opened the doors and said, "You two can come in now."

They both walked in and saw their mother exhausted but happy with the small bundle of blankets in her arms. He is a big baby, no wonder why the screams were louder than he remembered.

"Illuto, Illumi come closer and meet your brother," Kikyo told her boys.

They came closer to the bed and saw the very chubby cheeks of their brother's.

"What's his name, Okaa-san?" Illuto asked.

"Milluki, Milluki Zoldyck." Was the answer from their father.

"Illuto, what are you trying to create?" A voice came from behind.

The white-haired boy turned to his Father.

"A move called Shadow Step. I have been practising for a while now, Otou-san. Do you want to see?" Illuto said.

"Ho?"

He concentrated his Nen to his shadow and slipped in, Illuto appeared in a totally different location, the shadow made by the water bottle. He emerged from the shadow, regaining his body once again.

"Indeed, this would be very convenient considering our line of work," Silva commented.

When Illuto notice the lack of his grandfather he asked, "Ne Otou-san, where is Ojii-san?"

"He had a job to do, so I am filling in for today," Silva said.

"Oh, okay."

Silva thought to himself for a moment and then said, "Now, Illuto I want you to come at me with everything you have learned."

"Understood, Otou-san."

While Illuto doesn't know the full strength of his father, he certainly knows Silva have daily reports of the progress of his training. With the limited information from Rena, Illuto knew he wouldn't be able to land a hit on his father. But Illuto still needs to impress his father.

"Come, Illuto." Silva commanded.

With that single sentence, the white-haired boy immediately threw together a plan. His aim is to reach the switch to close the lights, heightening his control over the darkness will give him better mobility in his terrain.

With a gleam in Silva's eyes, Illuto knew Silva knows his plan.

'Ah, he already figured it out. Damn.'

He has no choice but to use the limited shadows to maneuver around. And with his natural speed, he won't know if he could get around his father.

Illuto dashed head straight to his father. If this goes smoothly, he could distract his father and using that chance he could go straight to the switch. Thus ending the spar. The heir lifted his arms and gave a punch but to be blocked. He then twists his body to kick his father's head but to also meet thin air.

'Tsk…' This was getting frustrating after a while, but he must stay calm. If an assassin could not keep his cool then, they're not worthy to be called an assassin.

His father isn't even breaking a sweat and still has his awareness up.

'Damn, his father is a monster.'

With a breath, he calmed his body and mind.

'Wait…' He thought in realisation. 'I could use that! I don't want to use it on family, but I have no choice.'

With a new set of determination, Illuto manipulated nen. Coating his hands, he rushed to the shadows where his father stood. He gave a brief feint at his father's arms and was dodged, with this golden chance he went directly to the shadows of his father.

He then proceeded to rip the shadow, thus rendering the current head's left arm useless. With the new opportunity, he attacked from the left side.

His punch connected with Silva's face, but...

"Illuto, you've gotten strong…" He heard his father spoke.

Before he could react he was slammed down to the floor. The young heir could feel the tremendous force that was behind the grab.

Silva eyed his son and loosen his hold, "Good job."

Most certainly the match was over and he had lost. But thrill that he got from the fight…

...It was addicting…

Unconsciously he let a grin slid on his face. But when he noticed, he stopped the smiling. This is not like him, he shouldn't be grinning. He never grinned before.

"Otou-san, what's this feeling?" Illuto asked.

Silva observed his heir. His son is undoubtedly the most serene child he has ever seen. The fact when a grin had appeared on his face, Silva couldn't believe when the kid started to ooze bloodlust.

"You're emitting bloodlust and the fight got your adrenaline pumping." The older white hair answered. "What you're feeling is the desire to defeat stronger opponents."

"Oh, I see. Then I must control myself, it might interfere with my work." Illuto responded, then he remembered that he had to give back his father's shadow. "Ah! Otou-san, let me fix your arm."

Silva watched as his son grab the darken transparent air and walked to him, he got to the ground and reattached the shadows. He then can now move his arms again.

'What a power…' Silva though. 'What did my father taught him?"

Zeno is teaching a monster in the art of assassination.

End.