Sinners' Game

Everyone around us, in the heart of more or less there is a heart demon. Every season, a mysterious man who calls himself Psychiatrist goes looking for seven people with different demons to play a lethal game. Those who win the game can be satisfied with any requirement. But why is it that the manipulators behind the game can do such cruel deeds? Why is it that this game of battle is to be held? And how widely does it influence?