Unpopular opinion here but I have a mixed bag of feelings for what happened here. Yes, AS AN ADULT, Eunhan made some real bad choices and deserves punishment, HOWEVER, not from this ghost, AND DEF NOT BECAUSE OF HIS WISH TO THE GHOST. Eunhan was a child, who was deceived by this evil spirit. Nobody could tell what wishing to be the MC would mean to harm him.
So yeah... for all the deeds done as an adult, Eunhan can get all the punishment for all I care, but not for this.