He's needed to make bong soon gain more confidence in her power i think. but i do think that the serial killer is a bit too scary for this typr of drama. So much gore in his scenes.. yuck

I think it is necessary, so that DBS can flaunt and use her super strength throughout the series. And I love the part when the 3 leads team up together to defeat the main villain, that was so cool.  The writers could have explore more of that. They could have made the plot line more smoother, more compact, instead of throwing a lot action challenges to DBS in all direction. 

Even after one year .. am still seeing this beautiful drama.... I have seen many haters for this drama....... but I love it... bong bong and min min was best couple...He is most cheesy hero ever in k drama...