Hmm entertaining watch, but a frustrating one. I don't regret watching, it's a lot of fun, the action scenes are choreographed really well and the budget and visual effects make for amazing viewing! The pace of the action scenes is really good and keeps you hooked but there were just so many elements of it that were so frustrating.

I think the main issue was there were too many episodes but horrendous use of time... so many characters were introduced whose storylines went literally nowhere (the two cops and the children, the schoolgirl who gave birth, the politician, even Onjo's father whose storyline was built up so much for the most ridiculous and avoidable death ever).

It was so full of plot holes as well like it's actually screamworthy watching the inconsistencies with the 'halfies' which was never explained beyond one comment that the only thing stronger than the virus was human will? Or something like that but the characters' individual drives weren't all very clear. Generally I think Gwinam made a pretty good baddie I believed his motivation that he was so inherently twisted and evil it was his drive to continue to cause chaos. I loved the good v evil rivalry with Cheongsang but it was super frustrating that he had some ridiculous inability to be killed that just proved uneccessary and repetitive, can't even count the amount of times he fell off a building and then recovered in 2 minutes. Whereas Namra's abilities apparently only appeared at the very last second to save them, even though there were so many avoidable deaths or failed plans that would've so easily been solved by literally anyone remembering she had superhuman strength and basically supernatural abilities. And then that weird bullied girl who became a halfie, failed to burn down the school and then ended up killed; an already unrealistic character arc built up only to go nowhere.
I really wish they'd had the bullied school girl about to burn down the school and then have Cheongsang and the group talk her out of it and make her realise she's not evil at heart so she ends up sacrificing herself protecting them from Gwinam. I think that would be the perfect showdown between the two 'evil' characters and redemption for her and his comeuppance. And then I think Cheongsang could've sacrificed himself for the group but his drive to protect his Onjo and his friends would be enough to turn him into a halfie too. I don't know.. so much they could've done with the characters and concepts but failed to execute.

Furthermore, a lot of the characters and dialogue was ridiculous I mean the amount of time spent on Onjo/Cheongsang pining when they were literally in the face of death. But I could excuse the vapid love stories because at the end of the day it wouldn't be a teen drama without them.

Generally I think it started really well, I liked the concept and I really like the main group and generally think the acting was good as much as dialogue allowed. I do think it was entertaining and I probably would watch S2 and while I generally thought the dialogue was good I'd probably account it to overambitious writing.