The Dark Rebirth of Pandora: Revenge of the Abyss - Chapter 5: Birth of the Demon King

I am the sword.

Killing a man amidst a thousand miles, no one dares take ten steps.
Killing a man amidst a thousand miles, no one can take ten steps.
Killing a man amidst a thousand miles, ten steps? Not possible!

I am the sword, the sword is me,
On the path towards heaven, each shall wield their own.

- Description from Novelupdates

As a promise, he went out into the world as an assassin. 3 years later, after becoming the Supreme Assassin, he gave up on everything he had and returned to the ranks of ordinary people. But one day, Kismet, a mystical game created by the National Research and Development had appeared.

Enigmatic hands, spectral frame, and one cunning strike just like the swing of the Grim Reaper. The Supreme Assassin takes on the mystical world, and how his legendary tales sets off, progressively ascending the altar to becoming the best.

- Description from Novelupdates

This is the story of Kir, who has to thwart the will of Heaven, Hell, and his parents in order to survive, protect the people he loves, and achieve happiness.He just has to make it through life at a magical academy, avoid dying, and survive to find his birth mother, the lost Daughter of Heaven. Or be forced to take his place at the side of his father, a Duke of Hell bent on destroying the way things are.It's a lot to handle for a quiet, brooding angel boy.Fortunately, he has company. A succubus, a foxkin girl, and a half-angel boy to start. And Kir has his own secret: this isn't his first go at life.

Hye lived his entire life without a class. After the apocalypse hit the human world, strange creatures invaded and killed humans while new lands were being added.

Systems were given to humans and with the help of the guides, humans started to fight back for their lives. All of this happened under the watch of the venerable beings who were shining stars in the sky; gods!

Hye dreamt his entire life of a chance to prove himself. He was a hard working, earnestly learning and smart youth. However, the apocalypse never was merciful to such humans at all.

Until one day he got a chance to go back in time, when everything started. At this new starting point, he found himself able to finally obtain what he wanted, a class for himself and power beyond imagination.

But will things be this easy for him?