User blog comment:EmrysOfAlbion/Emrys could have been smarter/@comment-4650675-20120503214738

I doubt that he does not want to kill her...in my opinion, he would have no dilemma killing her, since to him she is just another enemy of Camelot now, and a really strong one. The reason I think he did not do that is because he probably couldn't. First of all, he had to be in the same place with Morgana in order to kill her using the poppet. However, if he did, she would probably not just stand by and watch him killing her, she would do something. It was too risky for Merlin to stay near Morgana for too long, and the whole operation's success had solely to do with Morgana's magic being blocked, because if she could use magic the king and the future queen would die, so he may have thought "better be safe than sorry and just block her magic. She will die either way if she cannot use magic.".