In fanfiction, the backstories of Clare and Raki can be further explored. Writers might delve into their pasts more deeply. For Clare, her early days as a Claymore and the traumas she faced could be explored in relation to Raki. How does he help her come to terms with her past? And for Raki, his own journey and how Clare has influenced his view of the world can be elaborated on. This exploration of their backstories can add a whole new layer of depth to their relationship and individual characters in the fan - created stories.
Love and friendship are also very common themes. The fanfics usually explore the different aspects of their relationship, whether it's a deep platonic friendship or a budding romantic love. In some fanfics, they have to overcome obstacles to their relationship, which adds an element of drama. And protection - Clare is a strong fighter, but Raki also tries to protect her in his own way, which is often a theme.