Responses

Haha it's like this. In order for the curse to completely work, sooyeon must ONLY feel hatred in his heart, hatred toward his target. Other than hatred, he is not allowed to feel any kind of emotions towards other people during the duration of the cursing period. But since sooyeon was able to develop feelings of love towards dohui, it messed with the curse and was instead directed to him. As per the curse manual instruction, you must only have feelings of hatred towards the target for the curse to succeed.
The Brother thinks Sooyeon was cursing HIM, so he's the one Sooyeon would have to have feelings for in order for the curse to backfire on Sooyeon, so hooooow did he get to the conclusion that Dohui was to blame???? Excuse me????