like a lot of other people I started watching this for the leads Seo Inguk and Park Boyoung and these two didn't disappoint. they did deliver a great performance for the poor script of the show. I'd give this a 5/10 or less if it wasn't for them.

the second leads story was neither interesting nor did it add anything to the story but just felt like a filler instead. they tried to make it a "omg look at the secondary leads 3 good looking people in a love triangle" but failed badly. the other side characters were also pretty meaning less.
I watched Lee Soohyuk in Tomorrow and his stoic acting fit his character there but here his acting made his character even less interesting here, to me he's just one more of those actors that are there cuz they're good looking and draw attention but can't really act sorry.

Seo Inguk's character had so much potential he was the stone cold supernatural male lead that brought destruction with everything he did, but that lasted only one episode. most of the show you couldn't even see doom causing doom the only thing he did was teleport and time travel.
I watched this solely to see doom falling in love with a terminally ill cancer patient but I never really got to see him falling in love. one day he'd threaten her and they'd fight and the next day they say they're in love like it was mood swings every 30 mins and we never got to see their characters mold into each other, get that character development (esp cold hearted doom).

the character development of doom was something I really wanted to see but never did it was like he was a completely new person suddenly and no gradual change and it was disappointing tbh.
the god (deity) felt more like a villain or her character was just poorly made. none of her actions made any sense like what was she even trying to do??

also the plot felt very forced to bring out a love story like the FL suddenly deciding that she had to fall in love with the ML to survive... where did she get that from? and then suddenly deciding to live together but were technically living in two separate houses.

the dialogues were THE WORST. they were so corny and so poorly written you could even tell some were forced into the script just for some tears (they didn't fit in naturally). only kept watching this for Seo Inguk and Park Boyoung's good acting which really carried the entire show. though I found ep 9 & 10 pretty interesting cuz these two again carried.

I didn't really like the music, maybe it's just my personal taste but I feel like it had OSTs that I could swear I heard in another drama and were nothing special either.

OVERALL: if you're interested in a fantasy drama with a good plot and well written and interesting characters this is absolutely not for you. but if you wish to see it just for the leads' chemistry with each other, go ahead and watch it! though I can guarantee you that you can skip every other scene except theirs and you'll be missing nothing at all cuz rest of it is just a filler.