The worst thing about the end of the world is we did it to ourselves. Isaac Thoma lived to see the last handful of survivors defeat the demonic champion. He is now alone, his past in ashes, the last and most powerful human on a blighted Earth. But what if he could go back?

Hurled back in time, Isaac has one chance to change it all. A chance to warn humanity of their impending doom. A chance to stop the [System] before shortsightedness and lust for power can render humanity extinct. Facing malign deities, demonic hordes, and the unstoppable march of human greed, Isaac will give his all to prevent the end that has already happened on the day the world became quantified.

Without so much as a warning, humanity in its entirety was suddenly moved to another dimension. Every person without exception.

But this new world with all its opportunities and gifts of wondrous abilities, was a stadium. A deadly arena of an unimaginable scale. And Humanity were to be its latest gladiators. Every man, woman and child was given a weapon and ordered to fight. Stuck in this dimension without a way out, only two options existed for the would be hunters: Fight with monsters to complete the many trials ahead, or perish.

Faced with hordes of powerful monsters, thrown into battle with complete strangers at random, the unfair game of survival began. And from the very beginning, billions of lives were extinguished in mere moments. But even within this abyss of despair was a small ray of hope: If even one person were to complete every raid, then humanity would be redeemed and restored back to its former glory.

No save points, no revives, no retries. Everyone had just one life to make their way through the gauntlet of raids prepared to test their mettle. Within this marathon of death, one man becomes aware of an exception to the rules of the game.