I am thinking of starting a game based on the seven dealy sins:
Pride, greed, lust, envy, gluttony, wrath, sloth.
It could just be general to explore each of those 'sins' or could be the demon temptation thing as each of those sins has a demon who tempts and seduces us mere motals into committing that particular sin.
It's just been wandering through my mind for a while and popped out as an idea a few minutes ago, so I will write more on how I see it as soon as I have more inspiration.
Come my pretties be my muse.....