I wanna know something about CITY HUNTER drama ?

I know am late to ask about this drama :v but i started watching city hunter yesterday and i LOVE it ^_^ but one thing really frustrates me !!! I mean when he kidnapped the baby !! Its sooo wrong !! I mean even EVIL o.O he had no right to destroy his life ! Or his mother's life
Also i know the kid wont hate him when he knew the truth because he knows him as his father !! But still its so wrong !
Also also ! Why he didnt make his revenge by himself years ago !! Why raise the child and made him the one that do it ! He even was not there when they faced that fate 17 years before this is so frustrating :v
Am even astonished that the kid did what his "father" wanted in the end :v

PS: if this has something to do with the next episodes .. Don't spoil it then ^_^ plz thanx