User blog comment:Morganaforever/Finale/@comment-90.37.69.244-20111226154420

Excalibur was created by the breath of a dragon, which gives this sword a great power... so much so that the Kilgarrah made Merlin swear to hide the sword once the epic battle against the dead was over a few seasons back. Arthur won back Camelot welding excalibur and its power to defeat Morgana. Aithusa healing Morgana with her breath seems like an effort to maintain the balance of power.