The world of Gaus, where mana is abundant. Every human can cultivate skills and techniques related to mana as well as strengthen their bodies through mana. 500 years ago, the world of Gaus was a peaceful one, but, due to the sudden appearances of dungeons and the monsters it produces, humanity was quickly threatened with extinction, and fortunately, due to the heroes of Gaus, humanity stood still and created bases around the world to protect its citizens. Although monsters and dungeons are still present, humanity kept fighting and defended its own to avoid extinction.

After 200 years of peace, the world of Gaus has remained to be dominated by humanity, however, that was not actually the truth as the threat of the countless dungeons around the world is still present. And now, our own hero, who was reborn after his death from the Earth, will be blessed with a system and will fight these monsters to save the world and humanity from its pre-destined destruction.