One popular theme is loyalty. Merlin's unwavering loyalty to Arthur is often explored in a more romantic or deeply bonded way in fanfiction. Another theme is the power dynamic between them, like how Merlin's magic can both protect and complicate their relationship. Also, the idea of destiny plays a big role. Since they are so intertwined in the Arthurian legend, fanfiction might explore how their being mates is fated and how they fulfill their destinies together.
A common theme is sacrifice. In many fanfictions, either Merlin or Arthur is willing to sacrifice a great deal for the other because of their special bond as mates. For example, Merlin might risk exposure of his magic or his life to save Arthur. Adventure is also a theme. They go on quests together, and in the fanfiction, these adventures can strengthen their relationship in ways not shown in the original stories. Friendship evolving into a deeper relationship is another theme that's quite popular.
The theme of betrayal is often seen. Maybe Merlin is wrongly accused of betraying Arthur due to his use of dark magic for a good cause. Or Arthur might be seen as betraying his own ideals under the influence of some dark power. It adds a lot of drama and tension to the fanfiction. Also, the exploration of a post - apocalyptic Camelot where Arthur and Merlin have to fight against dark forces to rebuild their world is a cool theme. It gives a whole new dimension to their characters and relationship.
Well, a lot of merlin x arthur fanfiction focuses on the power dynamic between them. Since Arthur is a king and Merlin his servant, exploring how that changes when their relationship becomes more than just master - servant is a big theme. And of course, there are themes around protecting each other. Merlin always protects Arthur with his magic secretly, and in fanfics, this can be elaborated on more, like in situations where Arthur is aware of Merlin's efforts.
Some fanfictions focus on the theme of alternate universes. In these, the Merlin - Arthur kiss can happen in a completely different setting. For instance, they could be in a modern - day world where they meet in a different way than in the original story. Or perhaps they are in a world where magic is accepted openly, and their relationship develops more freely. This allows for creative interpretations of their relationship and the significance of their kiss.
One common theme is loyalty tested. In many Merlin - Arthur hurt fanfictions, situations are created where Arthur's position as king or Merlin's role as his servant put their loyalty to each other on the line. Another theme could be sacrifice. For example, Merlin might have to sacrifice his magic or his safety to protect Arthur, or vice versa. Also, the theme of friendship in the face of danger is prevalent. They might be hurt physically or emotionally due to battles or political intrigue, but their friendship endures.
One popular theme is unrequited love. Arthur might want Merlin but be unable to express it due to his status or other obligations. Another theme could be the discovery of Merlin's magic and how that affects Arthur's feelings towards him.
One popular story could be about Arthur and Merlin going on a secret quest that wasn't shown in the original series. It might involve them facing a new, powerful magical creature. Another could be a story where Merlin has to hide his true identity even more carefully from Arthur in a different set of circumstances. There are also fanfictions that explore their relationship in a more modern - day AU (alternate universe) setting.
There could be a fanfiction where Merlin discovers a new magic that he has to keep hidden from Arthur at first. It would add an interesting layer of secrecy and tension to their dynamic. This type of story often delves into Merlin's internal struggle between his loyalty to Arthur and his need to explore his magic freely.
In Merlin and Arthur marriage fanfiction, a common trope is the 'power couple' concept. Given Merlin's magic and Arthur's leadership, they become an unstoppable force when united in marriage. There's also the 'love - against - all - odds' trope. With Arthur's position as king and the often - complicated relationship between magic and the court, their love and marriage seem almost impossible at times. But they fight for it. Additionally, the 'reincarnation' trope can be used. They could be reincarnated versions of past lovers who are destined to be married again in this life.
One popular story could be 'The Bond of Arthur and Merlin'. It focuses on their deep friendship evolving into a more profound bond. In this fanfiction, they face many challenges together, and their relationship is tested but ultimately grows stronger.
There are stories that focus on how their friendship could transform into a BDSM - related relationship. It could start with a simple exploration of trust between them, like in a scenario where Merlin trusts Arthur enough to submit to his commands in a BDSM sense, while Arthur has to learn to handle this new power and responsibility.