Was interesting until they tanked it (spoilers)

The first half when he was in jail was interesting but when he got released it just felt different.  He's a leader of a criminal network but uses nothing. 

The whole build up where the guy was a serial but it was fake went nowhere.

The chairmans son went nowhere. 

the Dr wife who got killed went nowhere

The girl who got put into the mental house was dumb, she was so important but Big mouse didn't have people watching her?

The wife getting sick just to drag it out to die pointlessly,  when in the end they just went on killing him? They could of done that 6 episodes back

Way too many Korean shows dragging out episodes to end up just tanking it.

My theory about the chairmans son is that they introduced him or at least mentioned him just in case a season 2 is ever made. If there is a season 2 it would then make sense that the chairmans son who has already been established as a bad guy learns of the chairmans death and comes back to Korea thus becoming the main villain for the second season. Might not be the case but it was just a thought, i guess we will only know for sure if we get a second season

TBH I saw that whole Changho becoming the new big mouse plot from a mile away but it was still interesting. I just never thought that they would actually off the big guy just to get him there. His wife dying was mostly for plot reasons. I believe if his wife was alive he would have given up the position of big mouse as soon as Choi Doha was out of the picture. I feel like the satisfaction of all the evil people getting their karma was what was missing from it and that upset most of the people including me. 

The chairman's son on the other hand is a whole another thing. First and foremost I don't think they should have introduced him not to mention they killed off the guy who was the only one that could have been a witness against him. Second is that I feel like they left the mystery of Big mouse's daughter's death a secret. The chairman said he didn't like bloodshed and then he seemed to not remember her until his secretary whispered something to him. I honestly thought that since his serial killer son killed young women that it could be possible that he came across Big mouse's daughter while she was on the NR forum corruption case and killed her followed by the chairman covering up for him. Doesn't it mean that while Changho's revenge is complete, the original Big Mouse's revenge isn't. They left alot of plotline open ended while others were ended too hastly.