Chapter 1: Number 800.
In the depths of the Shiwan Mountain Range, existed a branch of the Cult Of Heavenly Demon that raised kidnapped or lost children to become new high level warriors for its cause.
They called it the Cave Of Latent Demons.
These trainings were harsh and inhumane to the point that scores of children died because of it.
This was the fate of Number 800, a boy who dragged himself back into his room after a hard day of sparring with the instructors.
Several bones were broken, his internal injuries were adding up over the past few weeks, and his newest injury, a punctured lung, finally brought him to the end of his rope.
"Urgh..."
Throwing himself on the stone bed, Number 800 coughed up blood as he leaned on the wall behind him, looking up at the ceiling.
"Damn...I don't think I'll make it...past tonight...gurgh!!"
Spitting out another mouthful of blood, Number 800 clenched his fists, with tears of blood running out of his eyes.
"I came here for strength...but I learned that I was so weak...now I'm going to die...gurgh!!...without achieving anything..."
Number 800's hand trembled in rage at his own weakness. Unlike the other children who were lost or kidnapped by cult members, he turned himself in to them in hopes of gaining enough strength to live a life that he had complete control of.
But now...this dream had seemingly come to an end.
The anger he felt as his bodily functions ceased could burn the world, but all he could do was rage in his mind. This was the end of the road.
Now, fate would have it that number 800 stay dead, ending his story here, but it didn't account for a certain variable.
The disembodied spirit of a woman that floated in the sky above the mountains captured his spirit as it was floating into the afterlife, her face filled with pity as she felt the emotions emanating from him.
"Such a tragic soul. No matter where I go...life is the same. No matter how different these worlds are, death is the same. I think..."
Looking down at the Cave Of Latent Demons, the woman floated through the mountain and emerged in the Number 800's room, her eyes locked onto his dead body.
"...it's time for me to make a choice. I've floated around these worlds looking for a vessel for too long. Child, I will give you another chance at life..."
The woman summoned a gourd and opened the corpse's mouth, pouring the liquid from the gourd into it.
Immediately, the spirit she captured flew back into the corpse, causing the corpse to suddenly spring back to life.
"Urgh!!"
The boys pupils turned red as his wounds rapidly healed, a small smile appearing on the woman's face as she saw this.
"Child, as you grow older, this power may drive you insane. You may come to hate me. You might want to die. But you will be unable to no matter how hard you try..."
The woman watched as Number 800's body floated in the air, convulsing rapidly from the liquid changing it on a fundamental level.
"...So, I will give you the ability to make that choice."
With a wave of her hand, a long odachi with a white hilt sealed within a black sheathe appeared and shot into the boy's body.
"This weapon is called the Black Mortal Blade. If you want to end your life down the road, then...this is your way out. But, if you somehow regain control over your mind in the future...this will be your greatest asset."
Her heart was filled with joy as she saw the boy's body floating down to the bed, his skin regaining a healthy hue.
Saving the life of someone so young with the last remnants of her power was a gift in itself.
"Oh! Since you don't know how to defend yourself...I will give you something that you will be familiar with."
With another wave of her hand, four books appeared in her palms.
The first was the [Ashina Esoteric Text].
The second, [Mushin Esoteric Text].
The third, [Shinobi Esoteric Text].
The last one was simply named the [Senpou Esoteric Text.]
She laid all four of these books down softly upon his chest, rubbing his forehead as she did so.
"I think with these, you will be just fine, Child. When we meet in the future, I hope you don't disappoint me."
Kissing him on the forehead, the woman turned into a column of light and flew into his body, seemingly disappearing from the world itself.
If anyone else saw this scene, they would be flabbergasted. This type of thing was rare in this world.
"Ughhh...."
Several minutes later, Number 800 slowly sat up, causing the books on his chest to fall to the ground.
"That woman...whoever she was...I'm grateful."
Even though he couldn't see her anymore, he remembered her words and her face. While he didn't understand everything, the most important part was that she gave him a second life. For that, he was eternally grateful.
Picking up the books from the ground, Number 800 immediately noticed that they were in a different language, but for some reason, he could understand it.
'Maybe it was because of the woman again.'
Laying them on the bed, Number 800 extended his arm and felt the presence of the blade within his body, causing it to appear in his little grip.
CLANG!
The weight of the odachi pulled his entire body to the ground, forcing him down to all fours.
"It's heavy...but it's enough. I will dedicate my entire being into mastering martial arts to become...the strongest. No..."
Number 800 had limited world experience. He couldn't even imagine what the strongest looked like or who it could be. The only image he had within his mind was that of the Heavenly Demon.
He had heard that not even the orthodox masters dared to fight him 1 on 1 because of his monstrous power. He could do what he wanted, say what he wanted, live how he wanted, and no one could tell him otherwise.
That was the kind of life Number 800 envisioned for himself.
"...I will become the Heavenly Demon! The strongest one there ever was!"