Villains also have a heart.

I know villains are meant to be hated but I can't help trying to find any good qualities on Min Ho each episode (It's Kijoon :)). He acts like a psycho, of course, but I think his father is the one whom made him like this. His "good" brother certainly did not help either.
In my opinion, his love for Yeon Hee and his son is undeniable. When he's with them is happy. Perhaps that's what he always wanted to have.  His life would have been so different if they had married...
I can't justify his crazy behavior but his life has been so hard and I can understand him a little. He's a patetic character, like Um Ki Joon said. I feel pity for him.
What do you think about him?

I get what you are saying.
I feel Ki joon did an amazing job in portraying Min ho! I enjoy how 3D he is as a character. He is not just the bad guy who does bad thing. He is the complete psycho that does crazy and frighteningly bad things. However, he is the guy who is insanely jealous of his brother, who seek his father attention and who truly loves his woman and his son. That's why his psycho side is even more scary because without that part of his personality, he is uncomfortably normal. I really want to applaud the complexity of this character and the wonderful acting. 
From my point of view, i think psycho in real life must be like Min Ho. If you cross their path during their everyday routine they must seems like normal loving husband or normal loving father. But, when you don't see them, they do the most horrible and frightening thing in the world.
For me, the father really gives me the creeps. He is like a more calm and inhumane version of Min Ho. I can only imagine all the horrible thing he must have done for his beloved company.
However, I don't pity Min Ho but I don't hate him as much as I should knowing all the horrible thing he did. I just feel that it is unfortunate that he chose such a path in life.
Also, I really hope Min Ho get properly punished. I want him to reach the bottom. I also hope that one day he will realize how bad what he did was but at the same time I feel that his insanity has reached a level where he can no longer turn back.
I really hope the father will lose his "beloved company". I think that will be the most severe punishment for him.
In the Ho family, the one I truly pity is the little boy. I can't help but wonder what kind of person he is going to turn into with a family like that.