Once upon a time, like in all fairy tales, a hero, slaying demons, helping the good and fighting the bad, having to put his on live on the side for the sake of humanity.
Of course he makes some friends on the road, he is liked by all, making piece rain on all humans, kill the demons and being happy forever.
And this cycle just continued on and on, eternally, without the demons being able to do anything about it for centuries, just having to be endlessly defeated.
Those demons, thirsty for blood, for revenge, for land, for glory and wanting to expend their domination to the human world and massacre everyone were just loosing every single time.
Every time they appear, every century, a hero and his companions, choosed by god will fight the demonic army and with every thing that god gave them, they would beat the devil pretty easily.
Nothing, no nothing seemed to be able to stop this dynamic, nothing seemed to be able to make the hero lose and the devil win.
But, isn't that normal, atleast that's what god wanted so that's just what will happen after all.
The advantages of humans were too big, far more and far better that what demons had, just imagine fighting a hero with "demoniac immunity" that just can't die due to any evil beast, you would obviously loose.
Then how ? Just how are you supposed to kill the hero with demons on your side, this just seemed to be mission impossible.
The only hope would be that other species would kill him before he annihilates all demons, but no one has any advantages on doing that, even considering that is even possible considering all his strength and helpers, even that seems impossible.
That was the problem on which the new demon king had to be thinking, him who just appeared on the south of every civilisation (humans or not).
His father died, his grandfather died, his great grandfather died...all of them letting after their lives the heritage of defeat.
Himself had to conceive a kid before going to war, the kid more than ready to take his place if he fails, but he doesn't plan on failing, he just had to find a wqy, a way to finish not like everyone of his ancestors.
By thinking about it, it was not the hero's companions who were deadly, not even all the human's army, that his followers and generals could eliminate them with the help of his two guardians, Hypnos and Thanatos
It was indeed the hero who was the problem, demons couldn't even think about scratching him.
At the start, like all others before him, his fate seemed to be sealed, but by wandering aimlessly in his territory when he first appeared, he thought of an idea that could maybe save his life, that could maybe make him win.
He wanted to create a special anti-hero force, in little territories close to the human frontier, in a litle village near the mountain and leaving despite being in a devil's forest, were humans.
In this place, too far to be interesting for any country, those humans will be his solution, he will train them and make them able to kill the hero.
If he did not make them entirely demons then even the priest and the sacred kinghts wouldn't be able to do anything, it was his gamble, an all in to make a slight difference and win.
With that, and knowing that he couldn't travel anymore before having trouble with other countries, he came back to the devil's castle, making this village disappear like it never existed and taking all those humans to train them.
By what he knew from his guardians, when the demon king appear the hero will always be 15 years old and it's at this moment that he get the divine benediction.
All the time before, the demon kings would attack the humans directly when he appears and try to annihilate everything before the hero become too strong, but it never worked.
Here the plan is to confise the humans by not moving, making it like they didn't even appear and prepare the army and resources necessary but more importantly to train his special unit.
He knew that the time was not on his side, maybe 5 to 10 years before the hero would move himself to take his head, but it was all that was necessary for those young humans to grow and become what he needs of them.
A plan versus god, a gamble that seemed very unlikely to work, here is what he had planned, and here is what happened.