One interesting plotline could be the knights and Arthur facing a new, powerful dark magic threat that only Merlin's unique powers can help them overcome. They might journey to a far - off land in search of a magical artifact Merlin has foreseen as the key to victory.
Arthur is the leader, with his sense of honor and duty. Merlin is the magical force behind the group, always using his powers secretly to protect them. The knights are like a band of brothers. For example, Gwaine is the fun - loving and somewhat reckless one, while Percival is the strong and silent type. All of them together make up the core of the story in this fanfiction.
Perhaps Merlin has to save the knights from a curse. He could go on a long journey to find the ingredients for an antidote while facing many obstacles along the way. He might have to outwit evil spirits or solve difficult riddles to get what he needs to break the curse on the knights.
Maybe a plot where Arthur and the knights get a glimpse into Merlin's past through some magical artifact. They see his early days of learning magic and the struggles he faced, which makes them understand his motives and loyalty better. This could lead to a stronger bond between them all.
One interesting plotline could be Merlin using his magic in modern times to secretly protect Arthur, who is a powerful businessman or politician. For example, he might use magic to prevent assassination attempts on Arthur.
One interesting plotline could be Arthur's initial shock and then his gradual acceptance of Merlin's new identity. He might start to see Merlin in a whole new light and realize how much power Merlin truly holds.
One interesting plotline could be their journey to discover their true family history. Since they are brothers in this fanfiction, there might be secrets about their parents or heritage that they uncover together. Another could be them facing challenges as brothers, like one getting into trouble and the other having to save him. For example, Arthur might get captured and Merlin uses his magic to rescue him, strengthening their bond as brothers in the process.
The main characters are Arthur, who represents the royalty and leadership. Merlin, the wielder of magic with a big secret. And the knights such as Lancelot, who is known for his honor, and Gwaine, known for his fun - loving attitude. They all interact in the fanfiction as the knights watch Merlin, and their relationships and actions drive the story forward.
One common plotline could be Arthur realizing his roughness is wrong and trying to redeem himself. Another might be Merlin getting fed up and leaving, which then makes Arthur see how much he needs Merlin.
One common plotline is Merlin using his age - related wisdom to save Arthur from various threats. For instance, he might have prior knowledge of a magical curse that's about to befall Arthur and uses his experience to counter it.
One common plotline is Merlin using his youth to his advantage. For example, he might be able to blend in more easily with the younger generation in the kingdom, gathering information that Arthur can't. Another is Arthur having to deal with his own insecurities about getting older while Merlin is full of energy. Also, there could be a plotline where Merlin's younger age makes him more adaptable to new magic or technologies that are emerging, and Arthur has to rely on him for that knowledge.