The Mysterious Child: An Adventure Tale Beginning with Numerology

"Big brother..."

She clutched the luminous stone pendant hanging from her chest and exhaled deeply.

The promise made that day was never kept.

Her brother, who had left saying, "Don't worry, it shouldn't be too dangerous," never returned.

He had said he would celebrate her birthday when he came back.

"Big brother..."

She had been unable to use magic since birth.

It was an incurable condition called magic element deficiency.

Unable to use magic, she was called "defective" and grew up oppressed. Although she survived thanks to the poison nullification skill she was born with, she had endured a childhood that made her wonder if it would have been better to die.

Mocked, abused, tormented, she was continuously hurt as a stress relief tool for the villagers. Her brother was the only one who protected her when even her parents abandoned her.

And now that brother too had failed to return from his mission.

Her brother was truly kind. He was straightforward and strong, and gentle even to the weak.

If someone had to die, she thought it should have been her - useless and on her second life - rather than him.

She couldn't help but think so.

She was a reincarnated person - meaning she had memories of her previous life.

She had once been born and raised as a human in another world, and was aware that she had talents that modestly speaking, surpassed others.

Just when she thought her life was smooth sailing, it ended abruptly before she knew what happened.

When she next opened her eyes, she was surprised to find herself a baby, but even more surprised that she was no longer human.

She had reincarnated into this world as a demon.

As she gained knowledge, she learned that the place where she was born and raised was called the "demon realm," a place separated from the human realm by a great forest.

She wished she had been born human. There were times when she agonized over why she hadn't reincarnated as a human.

But after repeatedly hearing from her brother that humans treated those with magic element deficiency similarly, her longing for human society eventually faded. Though she still wanted to meet humans someday, she couldn't leave the demon realm for her brother's sake.

All she could do was endure.

A demon who couldn't use magic was treated as less than garbage.

Even so, she continued to swing her sword relentlessly, relying on the memories of her previous life - when she was Onitsuka Tsurugi.

As if her soul was cursed, she was short in stature and poorly built just like in her previous life, unable to use magic, and truly the weakest demon with only poison nullification as her skill.

She was continuously oppressed by those around her and nearly killed countless times.

"You're a disgrace to demonkind!" 

The villagers had told her this many times.

Still, she endured and honed her sword skills.

This was all she had. She continued to swing the sword she had cultivated since her previous life, keenly sharpening her strength while living with her power hidden.

She had lived quietly without conflict so as not to cause trouble for her brother.

...Until now.

"Big brother... Nagi has become strong."

Having lost her brother, she made her resolve.

An unusual appearance with a large sword on her back despite her small, girlish physique.

Now, lying before her were the dismembered corpses of demons.

They were the remains of the villagers who had tormented her since childhood.

Aware that she was falling into the path of carnage, she trampled their corpses.

There was no anger or indignation. She had simply killed them because they tried to prevent her from leaving the village.

She didn't shed tears for killing her own kind. Her heart remained unmoved.

Had her heart become stronger? Or perhaps weaker? She didn't know. She couldn't even be aware if she had any hesitation.

Still, the skills she had honed until now did not lie. Even if she couldn't believe in herself, she could believe in her sword.

"Big brother, Nagi has become strong. So please rest easy and sleep peacefully in heaven. Until the time comes when Nagi goes to hell, please watch over Nagi..."

Clutching the luminous stone keepsake from her brother's cupboard, she began to walk.

From here on, she would walk the path of carnage.

To kill the high-ranking demon Saturn who had sent her brother to his death - and to defeat whoever had taken her brother's life, she decided to fall into the path of carnage.

Her name is Nagi.

She's just a low-ranking demon girl who can't use magic or skills.

Born with nothing, she continued to swing her sword relentlessly, loved by the sword, and cursed by the sword - an ill-fated girl.

The path she stepped onto was one of revenge against this world that had made her brother unhappy.

And so began the revenge of Nagi, the girl scorned as the weakest demon.

The protagonist Nagi from the spin-off work "Child of Demons ~I Couldn't Use Magic, But I Mastered the Sword and Took Revenge~" has appeared. Please treat her well. (※This is a lie. It's just her first appearance.)

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Author Notes:

  [Nagi]

  > Demon. 18-year-old female.

  > > Formerly Onitsuka Tsurugi. Once a classmate of Ruruk (Nanairo Gaku) and best friend of Saaya (Ichinomiya Azusa). Already appeared in the prologue. Even in her previous life, she had high physical abilities and was called "Onitsuka Invincible" when she won the national kendo championship three times in a row.

  > > > Because she reincarnated as a demon with magic element deficiency, she grew up being treated terribly in the settlement. She adored her brother, but when he was reported dead on a mission, she decided to leave the settlement. At that time, she was obstructed and persecuted by 34 fellow demons from the same settlement (including her parents), so she defeated them in retaliation. By the way, the name Nagi was given by her brother, who was a mid-ranking demon, with the wish that she would "become a gentle and kind child."

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