Kim Taehyung never could appreciate what he had received from life. Neither as a young and talented prince at the ancient Silla, nor as one of the deadly Sins. And it doesn't change during the WWII, either.
When Hitler's closest men find the lost box of Pandora, the situation offers him a perfect opportunity for enslaving his fellows. Although, there is something he wasn't aware of.. Pandora's box is more mighty than he thought at the very beginning and he needs a particular, pure soul to rein its enormous power. He uses her like a child plays with his toys. Flippantly and constantly. And eventually, those fake kisses become so tasty it almost feels real.
What would you do if you would have to choose between power and love? What if greed's in your nature? Could you resist the inner hunger and compromise for the first time in your life? Or you would risk everything even if it means you can lose everything you care about.
He believes that he can get both. Love and power all at once. After all, they are only sweet when they truly complement each other.