M Ginny

hi! it's not available in any streaming site, but you can watch it here (be careful with the ads and all that!) https://dramacool.bz/drama/proud-of-love.html

I didn't understand that about Yoon Su too, but I think that the Doctor didn't shoot Chin Hoon because he actually didn't want to kill any of them, he wanted to twist their minds as an experiment, so if he killed one of them he would lose the chance to see if that person could have possibly become a "monster" as well.