The best of the series is that Song Kang plays the part of an ethereal being (Gu Won) who can convince people in desperation to sign demon's bargain very well and handles both the emotional and humorous parts of the story compellingly and delightfully, whereas his co-lead Kim You Jung does not play a convincing 28 to 32 year old age range CEO (Do Hee) at any point in the story, with no gravitas, charisma, or authoritative aura. She is pretty miscast, the role would have been better served by an actor that's actually around that age or can play up that age. The writing for Do Hee and the show as a whole is not that much better, with her being morally repelled on things based on the needs of the writer in that moment rather than as anything that she particularly stands for consistently or confronts to change her mind. Part of the reason for this is probably because the show itself doesn't want to examine too closely how Gu Won enables a lot of evil doing in the span of a decade in exchange for taking the soul as well as damning desperate kind people to hell. It seems that he may have a choice, but that's a dangling plot thread never fully addressed. There's so many and I'll touch on some in a bit. Both the actress and writing does better for Wolshim, which would have made sense if she could have brought in a bit more of that character's strength of will into her modern day incarnation being as they are the same soul, but it doesn't happen.

There is also a lack of chemistry between Gu Won and Do Hee, which could be overcome if the characters had connection, but the writing doesn't develop that nor does it define the rules of it's supernatural world and it's stakes very well. People go to hell, but what that entails isn't explained. What was Gu Won's experience of hell? How did fisherman guy get out to reincarnate to make the same deal again and how did he become Gu Won's butler? Is the sentence in hell temporary or does it depend on the crime? Do people of all faiths go to the same hell? Or does it only apply to people in the Catholic faith? The reasoning between how the transfer of Gu Won's power to and from Do Hee occurred is also ill defined and then also did nothing with the premise of him dealing with life without his powers. It's merely an inconvenience as he still has access to it through Do Hee and he's also very financially secure with his art foundation where he also lives and also really just so the character would hold hands, but nothing more that affects Gu Won on a deeper level.

At this point, every kdrama has a serial killer plot and so does this one. I thought the ambiguity between the actual mastermind being son Do Kyung or the father Seok Min at first to be a good way to keep the sense of mystery, but they reveal who it was way too soon and Seok Min is just the stock over the top villain afterwards. It was weird how at the end of the drama they show a scene remembered by the mom Se Ra about Do Kyung and her like they were a relationship the show cared about all along, but they weren't. There were extremely extraneous sub plots that did nothing to service the story as well like the sister Soo An being extremely jealous and obsessed with Do Hee and the entire mafia that is obsessed with Gu Won. The weren't even useful in finding the other killer's identity as the police did that just fine. Ga Young's obsession with Gu Won was also really annoying more than anything. There is also nothing to build on her current relationship with Gu Won aside from being his actual stalker that even the show called out. They aren't even shown as friends but at the end it's supposed to be touching that he says goodbye to her. She tried to get his wife to take poison pills. If all these subplots weren't used to develop or parallel the main characters as people then everything is so mind numbingly surface level and wasted screentime and storytelling potential.

The ending is so frustratingly lazy. There is zero reason for Do Hee to block the shots for Gu Won. The show didn't even try to make it work by making them magic bullets that can kill a demon or something. It's just something to force Gu Won to make a decision that causes his combustion. The way he's brought back is also extremely anti-climactic. So it was because he won a deal with God, but why didn't that just immediately kick in? Why three years? Why did god have the wait three years? Everything is so arbitrary and meaningless. I initially had a slightly higher rating for this drama, but the more I think about it, the worse it really is. To end on a positive, there is one storyline that the drama actually did good on and it is Chun Sook, Do Hee's adoptive mother. The actress played the conflicting love and guilt toward Do Hee so well and the mystery of what she did had a full circle connection back to Gu Won. Her memory of seeing Gu Won collect on Do Hee's dad's deal was a great reveal. The timing of withholding and revealing this information was good too. She felt like a full person despite the shorter amount of screen time compared to the other characters. Again potential for the drama to be better is always there, but they always kept going in the opposite direction.