Warning: Before reading this story, please understand that it includes canonical violence and sibling incest regarding the main character. Please do not read if you are uncomfortable with any of these. I do not appreciate hateful comments, so please just turn back now if you are against reading it. Thank you.

"Father! My baby is growing up so fast, Mommy is so proud!"

"Miss, try to stay still while I bandage your wounds. Please, we must do this before it becomes infected."

"My precious baby makes me so proud, as always! What a wonderful man he's becoming!"

Sitting silently within all of the chaos of their home, a small smirk curved on plump lips as dark eyes surveyed the panicked bodies around her. She sat sipping on her tea calmly while her mother screamed joyfully as the butlers tried bandaging her bleeding face, her younger brother whining on the floor despite his injuries already being dealt with.

"Nallu," a monotone voice spoke right beside her ear, the owner seemingly appearing from thin air.

The girl turned her face to be greeted with the blank stare of her brother, identical eyes staring at one another from their close range. They were so close that their noses were close to touching, and she could feel his light breath against her lips. She gave him an innocent expression, tilting her head slightly to the side.

"Illu, can I help you?"

Illumi stared back at his sister with unblinking eyes, their colouring giving off an eerie vibe as no pupil was visible, only a bottomless black. Nallui wasn't the least bit intimidated and only stared back with equally blank eyes.

"You knew Killu was planning on escaping, didn't you?" he asked, eyes narrowing ever so slightly.

Nallui blinked once at the accusation, not giving anything away on her face. "Did I? How did you reason that?"

"Killu trusts you," Illumi stated. "You do not seem worried about his sudden disappearance," he added.

From that perspective, it did seem rather suspicious on her part. Nallui was rather taken with her younger brother, and while others would call her obsessive, she liked to think it was a healthy dose of sisterly care. She leant in closer, their noses bumping against one another as she stared with the most innocence she could, something rather difficult when her brother knew just how little innocence she truly had left.

"Killu can take care of himself. We taught him that, did we not? Besides, don't you trust me, oni-chan? You know I would rather kill myself than let anything happen to him."

Illumi seemed placated by her statement, recognising the truth to her words. It wasn't a secret just how possessive they both were of their younger brother, both finding a sense of obsessive need to keep constant attention to him.

"And when exactly can we expect him back?" Illumi asked quietly.

Nallui rose a single thin brow in response and Illumi understood. Nallui didn't know. Either that or she wasn't willing to say.

Illumi's hand rose to hold a thin strand of silver-white hair between his fingers, the colouring a stark contrast to his own. The rest of her hair fell in a straight sheen to her waist. Despite being twins, Nallui and Illumi were like yin and yang, at least in terms of their colourings. Their facial structures were practically identical – both having wide dark eyes that could frighten anyone at their blankness – yet Nallui had been gifted with their father's light hair, something she knew would have gifted her the opportunity to become the next Zoldyck heir had Killua not been born.

Women had no place being the heir to the family. Not that Nallui minded. She didn't think there could ever be a better-suited heir than her precious Killu. Nallui didn't care for the symbolism her colouring gave her in terms of the family's dynamics, she only had eyes for the connection it naturally gave her with her little brother.

Illumi stared at the hair intensely, curling the silky lock around a digit before letting it slip through his fingers, cupping a cold hand to her cheek. He brought his mouth close to her ear to whisper lowly.

"Our perfect family cannot happen if one is missing."

His breath sent a delightful shiver down her spine and she moved her face to the side, feeling those cold lips against her cheek. She copied his actions, tucking the pin-straight black hair behind his ear and moving close, her lips kissing his ear. "I let him go because he wanted to. I will never deny him anything. A mother doesn't deny their children, Illu."

A mother and a son. Nallui didn't want another brother in their dysfunctional family. She wanted a son, and she was adamant on creating their perfect family which was only reserved for herself, her twin and their siblings. With Killua at the centre of it as their head. The true Zoldyck heir.

She couldn't be more proud.

And after all, is it not rational that Nallui would think of Killu as more her child than their mothers? Was it not obvious that she was meant to feel this way when their appearance was so strikingly similar? It was clear just how much Killua took after herself rather than Kikyo. Nallui only felt it natural.

"Would you deny me, Illu? Would you see our family in tatters before it can truly begin?"

Illumi cupped her face tighter, his fingers digging into her jaw with hidden strength. "I cannot deny you anything. You know that. I'm creating this family for you, aren't I?"

Nallui let out a smile at his words, ignoring his blank expression and pressing a kiss to his cheek. A thank-you.

"Let our cute little brother have this new sense of freedom. You know mother and father will order his return before long."

"I am to take the hunter exam. For my next mission."

At his words, Nallui stilled. Her encounter with her younger brother not hours ago running through her mind at his words. Killua's words about his intentions after his escape at the forefront of her mind.

The Hunters Exam.

"Where do you plan to go, Killu? I'll let you have this freedom but you know I can't let you go if I'm not sure you're safe."

A moment of silence.

"You know you'll have to come home eventually, right?"

A sigh.

"I know. Can't I just have a little time to enjoy myself? Act normal for once?"

"If it's what you wish then you know I'll give it to you. Anything you want I'll give you."

A pause. Hopeful eyes looking up at her.

"Can you keep a secret?"

A nod.

"I'm going to take the Hunter's Exam."

"Ah," she muttered, bringing a finger to her chin in thought. "I suppose I will join you."

"Any reason why?" Illumi asked dryly, though she sensed a hint of sarcasm dripping from his words.

Nallui smiled benignly at her brother, stroking a finger across his pale cheek. "Do you have no trust for me, Illu? Can you not indulge your dear imouto in her whims?"

"Zoldyck's do not have whims."

"This Zoldyck does."

The twins stared at one another, both understanding the other well enough to know this game they played far too often. Illumi knew Nallui wasn't being truthful while she knew her brother was smart enough to figure that out.

"You will go disguised." His words came out as a demand despite the monotone and Nallui knew arguing this point wasn't worth the effort. Her brother was controlling and had his ways to stop her from going if he truly wished it. She conceded.

"Fine. When do you leave?"

"In two days."

She hummed. That would give her enough time to construct what outfit she'd wear to disguise herself. She knew if her little brother was there she had to ensure he wouldn't recognise her before it was the right time. She'd let him have this small freedom. He needed to experience this if he were to truly become the next head of their family.

Illumi's eyes scanned her face, running across high cheekbones and wide, dark eyes. An identical face stared back at him, the only difference her softer cheeks and long eyelashes. The striking silver hair that tumbled down her back. A single finger ran under her eye, causing her lashes to flutter. She looked at him questioningly at his actions.

"You will stay with me during the exam. You will not leave."

"Why do you speak like I wish to leave? Have I ever given you a reason to believe I desire being anywhere but at your side?"

"You should only be at my side."

"And I am. Always."

Illumi's eyes flashed with a mixture of satisfaction and desire, so briefly she barely caught it. Nallui knew her brother just as much, if not better, than herself. She could recognise objectively that their relationship was twisted. Despite being sheltered upon Kukuroo mountain, Nallui had been on enough missions to know how sibling relationships were supposed to be. Especially twins. She knew it wasn't normal to be so close to someone you were born with and that to be so intimately entwined with them was unhealthy and unnatural.

But the Zoldycks had never been normal. They were a family of assassins, trained from birth to be nothing more than killing machines. What was an unusual relationship between siblings compared to the blood that covered their hands? Their family consisted of the most unhealthy of relationships no matter which two people you picked and so Nallui ignored the voice in the back of her head that whispered of corrupted affairs and obsessive love.

They were family. That's all Nallui had ever wanted, a family. She refused to accept parents that were willing to torture their own children and a pathetic excuse for a mother that was good for nothing but screaming her delusions beside a distant father. Nallui had plans to create her own family, with herself and her brother at the top. Once her little Killu came home and finally took the position as head, their perfect family could finally begin. A family with only herself and her siblings. Nallui would convince the stubborn Milluki that there was no need for their mother in their new family, and she knew Kalluto wouldn't mind so much – especially when reassured by his doting older sister.

Alluka could finally be released from her prison. Another mark on the list of wrongs their parents had committed. Nallui would welcome her little sister into their perfect family, despite her fear of Nanika. It was a fear brought by ignorance, she knew, not having spent much time with the being that had latched itself onto her little sister. Too busy with a mission that had lasted a couple of years to have truly bonded with the entity. Despite that, Nallui would learn to bond with Nanika if it meant Alluka felt part of their family. Nallui was the perfect mother like that. She knew what her children wanted and had no reservations giving them it. Even if her brother was adamant on refuting their sister's place as family, Nallui was prepared to force him to accept it.

Nallui stared at Illumi, who had now turned away to face their crying mother and a whining Milluki. The boy continued pouting to their mother in hopes of some attention. It was a pitiful sight not deserving of the Zoldyck name, but Nallui could forgive the boy for craving something so rarely given. She would give the boy the attention he wanted once it was time. She would make up for all these years of neglect. Illumi was stone-faced at the sight, not a shred of care for their plight.

Nallui moved forward to press a kiss against her brother's pale cheek, lips lingering at the loving action. "I'll go and prepare. I'll come to your room when I'm done," she murmured quietly before standing to move away.

Her lithe form moved gracefully from her seat and toward the door, blatantly ignoring the miserable sound of her brother's incessant complaints and the shouts of her mother calling her name. The click of heels was all she focused on as she exited the room, a content smile at her lips with the thought of seeing her precious Killua so soon.

I just want to make it clear that there aren't any untoward feelings regarding Killua or anybody underage in this fic. I only wanted to focus on an older HxH character, as they are always much more messed up and twisted (Illumi and Hisoka, for example.) Nallui's obsession with Killua comes from a sense of duty (her parents would have stamped it into their heads to protect the heir), love (Nallui loves all her siblings passionately) and genuine envy of her mother's ability to have so many children (a plot point that will be addressed later on.

Thank you for reading and please do not leave negative comments.