The sigil could be a symbol of trust. Arthur giving Merlin his mother's sigil might mean he truly considers Merlin as a close and trusted friend. It could also be a form of protection. In the world of fanfiction, perhaps the sigil holds some magical power that Arthur wants Merlin to have for safety.
Well, in fanfiction, this could be a major plot point. Maybe the sigil is a key to some mystery related to Arthur's mother. By giving it to Merlin, Arthur is involving him in something very personal and important. It could also be a way for Arthur to show Merlin that he's more than just a servant, but a part of his family in a way.
It deepens their bond. It shows that Arthur values Merlin highly enough to give him such a personal item.
In fanfiction, Ygraine is often a crucial figure. As the mother of Arthur and Merlin's connection to Arthur's birth, she can be a symbol of destiny. Her role might be expanded to show how her actions or even her existence influenced the fates of both Merlin and Arthur. For example, some fanfictions may explore how her death was not just an event but a catalyst for future events in their lives.
Well, Arthur could feel betrayed at first. He has been brought up to believe that magic is bad, and here his closest friend has been hiding this big secret. However, as he realizes how Merlin has saved his life and the kingdom many times with his magic, he might come to accept it and even see the potential of magic being used for the good of Camelot. For example, Merlin's magic has defeated many enemies secretly, which Arthur might now understand as a necessary protection for the kingdom.
Often in fanfiction, Ygraine is a complex character. She may be portrayed as a victim of Uther's desires in one aspect, but also as a strong - willed woman. When it comes to her relationship with Merlin and Arthur, she could be the one who unknowingly weaves their fates together. For instance, her death could be the starting point of a chain of events that bring Merlin and Arthur closer, and fanfiction writers can play with this concept in many different ways.
One possible reason could be a magical curse. In the world of Merlin, there are many dark sorcerers who might target Arthur. Another reason could be a poisoned weapon. If he was injured during a battle, the poison on the blade could make him sick. Also, it might be a result of some ancient plague that has resurfaced in Camelot.
In Merlin Arthur fanfiction, 'blue will still be blue' could potentially refer to the unchanging nature of certain elements. For example, blue might be associated with a particular character's magic or their loyalty. It could imply that no matter what challenges or changes occur in the story, this aspect represented by blue remains constant.
One possible secret could be that Merlin is a powerful sorcerer from an ancient and powerful magical lineage. Maybe his family has a long - standing connection to Camelot that has been kept hidden.
The tattoo might be a sign of his destiny. In some fanfictions, Merlin is on a grand quest, and the tattoo could be a map or a clue that leads him to fulfill that destiny. It could also be a mark of a pact he made, either with a magical being or for the greater good of Camelot.
In a 'Merlin and Arthur at Hogwarts' fanfiction, the story could start with Merlin accidentally casting a spell that sends them both to Hogwarts. At Hogwarts, Arthur is amazed by the magical creatures and the Quidditch games. Merlin tries to blend in but his unique abilities make it difficult. They both get caught up in a mystery within the school, like a hidden chamber that holds a powerful and ancient magic. As they explore, they discover that their fates are somehow linked to the history of Hogwarts, and they must use their combined skills - Arthur's leadership and Merlin's magic - to solve the mystery and find a way back to their own world.
It could be that Gwen unknowingly has some sort of magical influence over Arthur. For example, if there is some ancient magic tied to her lineage that she's not aware of, and it's causing Arthur to focus only on her and forget about Merlin. Another aspect could be that Arthur's love for Gwen is so overpowering that it's subconsciously pushing out other important relationships, like the one with Merlin.