But deep down: Morgana was once kind. The show reminds us by having her mock Merlin's loyalty: "Still his pathetic servant." That line hurts because it's true from her perspective — Merlin chose Arthur over her, and she never understood why.
This is noble. But the show argues that in a world of prophecy and magic, nobility can be fatal. Arthur dies not because he's cruel, but because he's good. His faith in people is exploited by destiny itself.
Merlin now knows the future but cannot change it. That's the core tragedy of Season 5 — the hero is trapped by foresight, forced to walk toward doom. 6. Arthur's Blindness as Virtue and Flaw Arthur's defining trait in this episode is trust. He frees Mordred (a former enemy), believes in his redemption, and refuses to see betrayal as possible.
If Mordred were evil, Merlin could warn Arthur. But Mordred is good . And the show is making a brutal point: destiny doesn't care about good or evil. The prophecy will use Mordred's love for Arthur (and later his love for Kara) as the lever that breaks everything.
That's the true bane of Arthur: not Mordred. But Merlin's helpless love. If you'd like, I can also trace how this episode sets up specific plot threads for the rest of Season 5 (Mordred's love interest Kara, the Disir, Camlann). Just let me know.
Merlin's final line in the episode (to Kilgharrah): "I've done everything you asked. I've protected him, guided him. But the harder I try, the closer he gets to Mordred. And the closer Mordred gets to him, the closer we all get to Arthur's death." Kilgharrah's cold reply: "Then you must do what you have always done. Carry on."