I love Ji Chang Wook's character Jae Ha. He was so fearless and I guess a bit reckless too but I loved that about him. He had such a presence that if you saw him, you'd definitely think that he's that one man you should not mess with without facing some serious shit. I hated the change in his character later on but whatevs... He still kicked butt.
Yoona's character, An Na, she played her well. I just wasn't really fond of her character. She literally seemed like a pawn being thrown around and used by everyone. xD
The character who stole the spotlight was Choi Yoo Jin, played by Song Yoon Ah. Such an amazing actress. I didn't hate her and that's probably because I didn't view her as the villain. There were times where I wanted to smack her but when I thought about it, she seemed like a pitiful person when you know her entire story. Could you blame her? She used everything to her advantage and as a woman, seeing her character, I enjoyed it very much because she had men on their knees begging for their filthy lives and doing her bidding. I loved that! :D It was fun watching her and the other guys go back and forth with each other. Haha~