Board Thread:General Discussion/@comment-96.49.230.4-20130106082616/@comment-4623180-20130106100014

Well why didn't Agravaine die earlier? This can't be answered, ask the writers directly. :(

And Morgana using the anti-magic slug on Merlin was a much better idea. If she had known Merlin was Emrys all along she would've tried much more evil tricks like this earlier. That's why he so desperately had to keep it from her- he became tons more vulnerable, see how quickly she managed to disarm him once she found out who he was.