After the first four episodes, I was well and truly invested. Although the modern-day setting lends the second season a different flavor, the callbacks and connections to season one occur gradually and organically, almost in sequence with Ho-jae's recovery of his memories.
The episode three action sequences. I understand that shrouding scenes in darkness are true to how the lighting would look in those environments, but when it's coupled with the rapid editing style of the fight sequences, it sometimes makes it difficult to follow exactly what's going on in those scenes.
Obviously, the budget was on the finale so the fight sequences were quite better and well-lit. Other than that, no cliche plot lines and good integration of past to present timelines.
This season is edgier and the storyline seems more compelling. Also feel like the chemistry is off the charts this time. Though the first season had good world building and layered characters, while this one has the complete opposite.

Seong Jo's motivation is so fucking stupid.
Why did Chae-ok not keep tabs on Tae Sang. I get the melodramatic we can't be together sentiment, but you would still like to be aware of the love of your life being dead or alive, which in fact would have helped her realise that he's also like her now.

I loved the twists though.