One common theme could be the origin story. How baby Deidara discovered his love for art and explosives. Another might be his relationships with other characters in his early days.
One common theme is the exploration of their opposing beliefs. Naruto believes in protecting his friends and village, while Deidara has his own view on art and destruction. Fanfics often play with how these two views can clash or merge.
The theme of forbidden love also pops up quite a bit. Given their different allegiances in the Naruto universe, a relationship between Sakura and Deidara would be considered quite taboo. Fanfics often explore the difficulties and the intense emotions that come with such a relationship.
Another common theme is the use of the 'lemon' element to add a sense of passion and heat to the story. It can be used to show the strong emotions between Deidara and the other character involved. Also, themes of self - discovery through love or relationships can be present. Deidara might learn more about himself and his desires through the experiences depicted in the 'lemon fanfic'.
One common theme is the exploration of opposites attracting. Gaara and Deidara are very different in nature. Gaara is more reserved and in touch with his inner self, while Deidara is outgoing and flamboyant in his own way. Their differences often lead to an interesting exploration of how they can come together.
One common theme is the exploration of their contrasting personalities. Itachi is calm and calculating, while Deidara is more impulsive. Fanfics often play with how these differences can either clash or complement each other.
Redemption is also a theme that can be found. Maybe Deidara, who has done some bad things in the Naruto universe, can find a form of redemption through his relationship with Gaara. And for Gaara, it could be about helping someone who seems lost. It's often about two broken souls finding solace in each other. The fics may also deal with the power dynamics between them, considering their different abilities and standings in their respective villages.
The theme of mutual understanding is quite common. In these fanfics, they gradually come to understand each other better. For example, Kurotsuchi may start to understand Deidara's passion for art and Deidara may come to respect Kurotsuchi's scientific knowledge. Another theme could be the idea of sacrifice. There are stories where one or both of them are willing to sacrifice something for the other in the name of love. Also, the theme of discovery is present, as they discover new things about themselves and each other through their relationship.
One common theme could be the exploration of an unlikely relationship between Deidara and Ino. Given their different natures in the Naruto universe, the fanfic might focus on how they overcome their differences.
One common theme is the exploration of unlikely friendships. Given their different backgrounds and personalities, seeing Itachi, Sakura, and Deidara form some kind of bond is often explored.
One common theme is the exploration of Deidara's character in a female form. This could involve how she interacts with other characters in the Naruto universe differently from the male version. For example, her relationships with Sasori or Itachi might be portrayed in a new light.