User blog comment:Dragoon leGreat/Gauis and Gwen- 5x12/13/@comment-4892425-20121128124441/@comment-5674726-20121129002410

''Maybe Gwen dies in With all my heart, and that hardens Arthurs heart, hence executes Mordreds love in ep 11. also weakens him for the battle of Camlann...hm..I dont know...''

If Guinevere is killed, I'd say that Arthur would end up gunning for Morgana and/or Mordred (depending on which is responsible) with every military asset at his disposal. Anger would drive him and could strengthen his resolve or lead him to make strategic mistakes because it's personal.