I score dramas based solely on my enjoyment of them, so my rating doesn't reflect the quality of the drama but how good of a time I had watching it. For me, Kokdu was a very long, painful ride.

I started the drama as it was airing and I hated it. Right from the first episode, it was obvious that the writing was sloppy and the plot was poorly placed. I was in a bit of a drama drought and tried to stick with it for as long as I could, but 4-5 episodes in I caved and dropped it. It was boring and while I enjoyed the ML for being a very out-there character, the FL was as sturdy as wet cardboard. But, oddly enough, I went back to it all these months later on a whim and, for some reason, found myself genuinely enjoying it. Was the writing better? No. The characters? No. All that changed was my mentality. I laughed at some of the jokes and had a grand time, and when the writing was bad or the pacing was weird, I laughed at that, too. If you don't take it seriously, it can be a pretty entertaining show. (The last 1/3 of the drama really drops off, however, and everything goes about how you expect so there's no need to force yourself to sit through it if you feel it's dragging.)

The biggest issue this drama has is that it doesn't follow through with any of its ideas. It'll throw plot twists and developments at you left and right without fleshing them out and then will forget about them just as soon. For example: the FL is a doctor, but she doesn't actually feel like one. She ends up opening a clinic, but the only time we see her doing her job is when it's convenient for the plot. By the halfway point, she basically isn't seen working at all.

Then we have Kokdu or, more to the point, the person whose body he takes over: Jin Woo. At the beginning of the drama, he dies and Kokdu has to deal with the affairs he left behind - his girlfriend, the plot of the villain, the FL Gye Jeol, etc. But partway through the drama, his soul is returned to his body by Gye Jeol's command. In this sort of show, this is something that often happens and makes up a big chunk of the story. But here? He's around for around 2 episodes, in which he discovers what's happened in his absence and decides to cling to life. This amounts to a whole lot of nothing. He dies again shortly after so Kokdu can take over his body and is never heard from again. There's no closure for him, he doesn't accomplish much of anything while he's around, and after he dies again no one really talks about him, not even the leads or his ex-girlfriend. It's filler.

This isn't the only instance of this, though. At one point, Gye Jeol's brother is kidnapped and the two leads go to save him. This is used as a trigger for Gye Jeol to finally realize that Kokdu's not human (which, how did she not notice this sooner??) and they begin their dramatic angst to waste even more time. And the brother? Well, when they walk off to have their angst, he's freed. Somehow. I guess. We're never shown if Kokdu went back to set him free, if he got out himself, or anything of the sort. Again and again, the story will introduce a plot thread or some side story and drop it just as quickly. Take the ending: Kokdu dies? No, he survives and is asleep in the hospital. No wait, he's actually awake and is staying past his 99 days. No, wait, actually, he's trying to get Gye Jeol to confess to him so that he can die. So what if he said he would stay with her no matter what half an episode ago? Oh, wait, he's dead again, for real this time. Except, of course, there's the mandatory time skip and he's revived for their happy ending. I didn't even mind the very end itself, but the lead-up to it was dreadful. There's also a point at the start of the last third of the drama where Kokdu stops being a fun character to watch and becomes more of the standard, brooding ML you often find in these shows, which killed a lot of my enjoyment.

Characters will say their opinion on one thing and change it at the drop of a pin. Kokdu remembers his little brother from his past life randomly, starts doting on his reincarnation for all of 10 seconds before he's shoved aside with no further development between them for the rest of the series. The second couple will fight over something randomly and then get along again. Actual plot points will happen off-screen and then will be explained to us lazily through exposition - or maybe not explained at all! I could go on and on about how hot-and-cold this drama is, but you get the point. All of these half-formed ideas get thrown in without being properly fleshed out and it really kills the drama.

So why am I still giving this a 7? If I have this much (and more) to complain about, then why not rate it to reflect that? Well, at the end of the day, for 2/3 of the drama I was enjoying it, even if it was a hot mess, and that's what mattered most to me. I laughed at how bad it got and enjoyed some aspects of it. The demi-gods were fun to watch, there were some good jokes sprinkled in, and beneath all the crap there was a sliver of hope that this could have been something. It feels like the rough draft of a story, just thrown together with a bunch of ideas that were never written out properly to be given substance, and if I think of it like that, I can move past some of its bad moments.

TL;DR: It's a badly-written show, yes, and the latter 1/3 is a slog, but if you're the type of person that likes watching bad shows now and then, and you want some turn-your-brain-off garbage to veg out to at the end of the day, give it a shot. And if a good plot with good writing is integral to your enjoyment?

Run the other way. Run as far as you can.