STORY:
The show has already gone different from webtoon in S2 so I wasn't sure how S3 will pan out and end but can say it didn't disappoint for most part even though I would have preferred had they gone by webtoon and ended it that way. The showrunners did one really good thing with this season and that was to not make it too messy just like S2. Things were kept at a good pace and weren't dragged unnecessarily.

ACTING:
Acting wise it was done phenomenally. Everyone did total justice to their roles be it the protagonists or antagonists. Song Kang nailed it with his portrayal of both Hyun Soo and his monster side. For me this time Min Si was the best in this season when it comes to showing off emotions, as she did so well showing her pain, desperation and sadness. Lee Si Young as a mother with conflicting emotions filled with desperation, guilt, pain and her relationship arc with her daughter was well executed.
Even Hong Suzu acted well in this drama than she did in "IH" so kudos to her on that.

PRODUCTION:
The production value was big and it showed quite well. The difference between S1 and S3 in terms of VFX and sets is quite visible.

ENDING/ FINALE:
It wasn't satisfactory but wasn't bad too. There are story arcs that could have been concluded way better had they gone by webtoon but then again the drama went in a different route way back. It is bittersweet to say the least.