If I remember correctly, the blonde guy said (I think his name was Jooyoung) that he was able to drink blood as a kid but as soon as he became and adult he couldn't drink any blood anymore, instead he got his energy/essence from s**.
If I remember correctly, the blonde guy said (I think his name was Jooyoung) that he was able to drink blood as a kid but as soon as he became and adult he couldn't drink any blood anymore, instead he got his energy/essence from s**.