In Merlin fanfiction, why does Merlin call Arthur sire?

One reason could be related to Arthur's relationships. If Arthur has a love interest or close friendships that Merlin wishes he could have with Arthur too. Like, if Arthur is spending a lot of time with a particular noble or a lady, Merlin might be jealous because he wants that same level of closeness with Arthur.

Well, in many fanfictions, Arthur might be overprotective of Merlin because of their deep friendship. They've been through a lot together, facing numerous dangers and challenges. Arthur has come to rely on Merlin in many ways, and he doesn't want to lose him. So, he becomes overprotective to ensure Merlin's safety.

In fanfiction, Arthur might be rough with Merlin because of a prophecy or a pre - ordained fate. He might think that by being tough on Merlin, he can prevent some bad outcome that he believes is related to Merlin. For example, if there's a prophecy that Merlin will bring great change to Camelot, Arthur might be rough in an attempt to keep things as they are, out of fear of the unknown.

Merlin could be heartbroken. He might retreat into himself and become more withdrawn. After all, he has a deep bond with Arthur, and this sudden break - up would be a huge shock.

Merlin would be very worried. He would probably stay by Arthur's side day and night, using his magic secretly to try and heal him. He might also search for rare herbs or magical items that could cure Arthur.

One reason could be for the continuation of his dynasty. In the context of Camelot, having a son would mean there is an heir to the throne. It would ensure the stability and future of his kingdom. Without a son, there could be disputes and power struggles over who will succeed him.

Merlin might have used his knowledge of the castle's secret passages. He could lead Arthur through those passages, away from the assassins. Also, Merlin could have called upon some magical creatures he's befriended, like the dragon, to help him. The dragon could fly in and either scare the assassins or carry Arthur to safety.

One possible reason could be a misunderstanding. Maybe Merlin did something that Arthur misinterpreted as betrayal or dishonesty. For example, if Merlin was secretly helping an enemy for a greater good that Arthur wasn't aware of at the time.

The banter between Merlin and Arthur in fanfiction is really interesting. It can range from light - hearted jabs at each other's habits. Merlin might poke fun at Arthur's love for jousting and how he always gets a bit too competitive. Arthur could retort by mentioning Merlin's clumsy attempts at serving him. Their banter also reflects the underlying respect they have for each other despite their different social standings. It's like a friendly sparring that keeps their relationship dynamic.

The 'Redemption' trope is also seen in some fanfictions. Maybe Arthur has made some mistakes in the past, and Merlin helps him to redeem himself. Or vice versa. It's a way to explore the characters' growth and development. And then there's the 'Battle Against Evil' trope where they fight side by side against dark forces, which really showcases their bond and loyalty.