Introduction: Zero was a victim of the war of harem.Two years of his journey as a demon in a world resembling a game he once played ended in a tragic death. Fortunately, his soul returned to Earth. Now, he was no longer Zero, the shadow villain, but Ernest, a runaway child haunted by an inferiority complex. Until ...[You must perform sexual cultivation if you want the curse within you to be lifted.]"We need to get married so we can do it.""You wanted us to get married so you could make me your furnace?"He ended up being a furnace for his new wife.  But, behind his role as a furnace husband, he gathered strength from the shadows to prepare for another catastrophe that would come....