A very well done concept with a novel, card-based game mechanic and is structured around a character's relationship with the Dark Lord. Are they able to escape their soul debt? Or, I guess you could also just embrace it and see how that is (i.e. the way some of us saw Vampire: the Masquerade as a superhero game). Choosing to fail and embracing evil is a valid method of playing the game. It really is focused on that narrative concept, which is a good one. With the 7 deadly sins as a framework, there's plenty of narrative space for characters to explore their own sense of evil.
The use of card decks instead of dice is certainly different (basically, pass/fail mechanic on high/low card, with a couple additional twists). The lack of a physical "inventory" is also an interesting choice, but it keeps the game timeless (which helps for generational play) and makes the storytelling focused on the central sin/virtue core of the storytelling.
(Yes, the game art in the PDF is definitely modern, but the rules are pretty generic about it, especially since it doesn't say that any skill requires any specific implement like a cell phone or a hand-and-a-half sword or whatever. So you could conceivably place this anytime, anyplace.)
It certainly falls into the story game mode, and less into the "kill things and take their stuff" mode of RPG.
If you're into the exploration of good and evil, and also interested in generational games (yes, the sins of the father do get passed down if you want to do the generational thing), then this is a good concept game for you. It's not like super-mega hardcore kind of game that beats you up with good versus evil, and the game does mention "Tone" - so you can think about going super straight dire/nasty storytelling, or consider a more slappy humorous tone, or a mixture (which is important, given the good vs. evil backbone).
[5 of 5 Stars!]