Summoned to another world as a sacrifice, 'Dan' lives on as a Dungeon Core and plots to overthrough this world's order who treats summoned 'heroes' as war assets. Leveraging his new existance to its fullest, he is both a 'hero' and 'demonking' simultaneously.  But what would you do with that much power in a world where heroes are weapons of the countries and kings are more threatening than demonkings?   Should he even help anyone other than himself in the first place? Not even his own OP prowess might be enough to see him, or the ones he cares about, through another day.  Will he be able to build his dungeon into a great kingdom for prosperity and protection?     Author's Note:  My first attempt to write a story, and largely based on the 'Dungeon Core' concept.  This story will feature Empire building aspects in addition to some personal growth of characters interms of power and character.