An Oracle, the Underworld Is Inside Me, I Become the King of Hades

He was born sick and weak, but because of an oracle, he became immortal and the strongest king in the world - the third generation of Pluto. Since all things are in chaos, how can he single-handedly build the underworld, the place where all creatures live after death? What? Hades is within me! So how should I build it? This novel and its characters are purely fictitious. Any similarity is purely coincidental and should not be imitated.