I didn't plan to watch this but couldn't resist the stellar cast. I'm especially fond of Kim Seong Oh, and he certainly delivered here. Overall, the acting was great, even Kim Rae Won, whom I haven't much liked since Gourmet.
The show started off strong, and I found myself very engaged. The science was asinine, but as my English teacher always said, fiction requires the willing suspension of disbelief. So, I suspended and went along for the ride.
It was a good ride until about halfway through, and it was downhill from there. With the rise of the cult sub-plot, The action got increasingly pointless, devolving into too many fights culminating with a blast of electricity from the electric eel man. (Like I said, bad science - even the creation of Spiderman made more sense.) The possibly very sweet love story between the princlpals also made little sense- one minute she's hating him for killing her parents, the next she's having his baby. There were places where the author was trying to write Frankenstein, but the whole cult bit ruined it all. The ending was not satisfying on any level. Where there could have been more development on the humanization of Zi O, it was just thrown away.
An Nae Sang was a marvelous mad scientist but his part petered out at the end - it seemed that the author got tired of writing for him and liked the cult leader better. By the 9th episode I was ready for it to end. Overall, it didn't live up to its promise.