I thought Season 1 was generally enjoyable, and Season 2 was also interesting, but had a little too many subplots and random characters. Season 3 fixes that by once again focusing on the most important character (Hyun-su) but doesn't give him much to do.

I'm really glad Hyun-su got more screentime in this season, especially with Eun-yu and Eun-hyeok, because these three were and still are the most important and most intriguing characters, but plot-wise, these three were pretty underutilized. I think the issue is, firstly, just not being quite sure what the end goal is. We know generally that they're on a crash course towards the antagonist, but I didn't really understand what the plan was. And secondly, between this season and the previous season, there's a pretty big shift away from individual stories and showing what triggers monsterization and how they should be dealt with. I get that it's difficult to do this once you've scaled up the story and there are so many arcs to address, but the unfortunate trade-off is that nothing quite sticks.