I really like 'Avalon's Arthur in Fate Fanfic'. In this story, Arthur has a deeper connection with Avalon, his mythical resting place. It gives a fresh perspective on his powers and his relationships with other Fate characters. Then there's 'Arthur's Allies in Fate'. This fanfic focuses on Arthur forming new alliances and how those relationships shape his journey in the Fate world. 'The Pendragon Legacy in Fate' is also good. It explores how Arthur's legacy affects the present - day Fate universe and the characters within it.
Well, 'Arthur Pendragon: The Fate of Camelot' is a great fanfic. It details Arthur's efforts to restore Camelot in the context of the Fate series. The author does a wonderful job of describing the new challenges Arthur faces in this different version of his world. 'Arthur's Trials in Fate' is another one. It's all about the various trials and tribulations Arthur must endure in the Fate universe, and how he overcomes them. And 'The True Arthur in Fate Fanfic' tries to portray the real essence of Arthur within the Fate framework, showing his true character and what makes him stand out among other characters.
Saber from Fate/Stay Night would be an obvious choice. Since she is also related to the Arthurian legend, there could be a lot of interesting interactions between them. They could compare their experiences as king, or even fight side by side against a common enemy.
One popular character paired with Arthur in Fate fanfic is Saber. Since she is an incarnation of Arthur in some versions of the Fate series, they often have complex interactions. Another is Merlin. He is Arthur's mentor and advisor in the original legend, so in fanfics, they are often shown having deep conversations and Merlin guiding Arthur through different situations. Also, Artoria is commonly paired with Arthur as they are both related to the Arthurian legend and can have interesting dynamics in the Fate fanfic world.
A good 'Arthur Pendragon Merlin fanfic' often has a strong portrayal of their friendship. For example, it might show how they support each other through difficult times. Like when Arthur is facing a tough battle, Merlin is there with his magic to help, and vice versa.
Maybe Arthur Pendragon gets transported to the Fate world and his presence disrupts the normal balance of power. The mages in the Fate universe might see him as a threat or an opportunity. He could end up being a wild card in the Grail War, not bound by the normal rules of Servant summoning. His noble phantasm, Excalibur, could be a game - changer in battles against other powerful Servants.
One interesting Arthur Pendragon OC fanfic could be about an OC who is a powerful sorcerer from a far - off land coming to Camelot. They initially face suspicion but end up helping Arthur in a great battle, using their unique magic skills. This kind of story can add new elements to the Arthurian legend.
One great 'Arthur Pendragon Merlin fanfic' is 'The Once and Future King' -esque story where Merlin's magic is a key factor in Arthur uniting the kingdoms. It shows their deep bond and how Merlin uses his powers to protect Arthur in a very creative way.
To create a good Arthur Pendragon OC fanfic, you need to pay attention to the writing style. Use descriptive language to bring the world of Camelot to life. Describe the castle, the forests, and the people. When writing the interactions between the OC and Arthur, show rather than tell. Let the readers feel the tension, the friendship, or the conflict through their actions and dialogues. And don't forget to have a good pacing. Don't rush through important moments but also don't drag out the story unnecessarily.
One possible plotline could be Arthur trying to escape the whore house and regain his honor. He might meet some unlikely allies among the people there who help him plan his escape.
There's also 'Female Arthur Pendragon: A New Reign' which is quite popular. In this fanfiction, the female Arthur has to deal with the politics of Camelot in a more nuanced way as a woman. It delves deep into the relationships she forms, both romantic and platonic, and how they are affected by her gender. The writing style is engaging and it keeps you hooked from start to finish.
There's also 'Arthur and the Star Wars Galaxy'. This one is a wild ride where Arthur Pendragon somehow ends up in the Star Wars universe. He teams up with Jedi and Sith, and his code of chivalry creates some unique interactions within the Force - using world.