User blog comment:Ḡwẵine Ḹٍٍkƨ Ĺiĸe Ͼềлȑềd/WORST plot hole in the HISTORY of 'Merlin'/@comment-4916403-20121014212601/@comment-4190137-20121015060338

Well, that's the plot hole...

Arthur forgot Mordred was a druid and he forgot druids have magic.