Often, in Bruce Wayne OC lemon fanfiction, there's the theme of the OC being someone who can break through Bruce Wayne's tough exterior. The 'lemon' part might be used to show a more intimate side of their relationship, which is different from the public persona of Bruce Wayne. Another theme could be the OC being involved in the dark and dangerous world that Bruce Wayne inhabits, and their relationship evolving in that context.
Common themes in such fanfiction may include the idea of the OC being a source of comfort or a new experience for Bruce Wayne. Since 'lemon' implies some form of romantic or sensual elements, these stories might explore how the relationship between Bruce Wayne and the OC progresses in that regard. There could also be themes related to identity, where the OC has to deal with Bruce Wayne's dual identity as Batman, and how that affects their relationship on an emotional and physical level.
One common theme is the discovery of self. The OC often enters Bruce Wayne's world and through their interactions, both the OC and Bruce learn more about themselves. For example, the OC might be a normal person thrust into the chaos of Gotham and in the process, discovers their own strength and purpose.
A prevalent theme is the protection of Gotham. The oc wife may either support Bruce in his mission or be in danger because of it. Also, the theme of identity is common. The oc wife has to come to terms with who Bruce really is. Moreover, the theme of sacrifice is often there. Bruce may have to sacrifice time with his wife to protect the city, and the wife may also make sacrifices for their relationship.
In 'dragon bruce wayne fanfiction', a common theme is the combination of the human and the mythical. Bruce Wayne is human, but the dragon part of the story brings in elements of magic and the supernatural. This can lead to themes like identity crisis, as he tries to balance his human self with this new dragon - related identity. There are also themes of adventure, as he might go on quests related to dragons, exploring new places and facing new enemies that are drawn to the power of the dragons.
One common theme is vulnerability. Normally, Bruce Wayne as Batman is seen as this strong, invincible figure. But in 'hurt bruce wayne fanfiction', we get to see him at his weakest, whether it's physical injuries like being severely beaten in a fight or emotional wounds such as losing someone close. This vulnerability makes the character more relatable.
Isolation is a big theme too. Bruce Wayne as a vampire often finds himself alone because he's different. He can't always be part of the normal world like he used to. Also, there's the theme of power. His vampiric powers can be a great asset in fighting crime, but they also come with a cost. He has to be careful not to let the power corrupt him.
One common theme is the exploration of gender roles. How a female Bruce Wayne would break or conform to the traditional male - dominated role of Batman. Another is relationships. Since she's female, her interactions with male and female characters like Alfred, Dick Grayson, and Catwoman can be very different. Also, there's often the theme of how Gotham would react to a female Dark Knight.
One common theme is the exploration of power. Harry has magical power and Bruce has wealth and physical combat skills. Fanfictions often look at how they use or misuse these powers. Another is friendship. How two characters from different worlds form a bond.
One common theme is the clash of ideologies. Superman with his more idealistic view and Bruce Wayne with his darker, more practical approach often have differences to work through. For example, in many fics, they argue about how to deal with villains, Superman preferring rehabilitation while Bruce is more about incarceration.
One common theme is protection. Bruce Wayne is always trying to protect his daughter from the dangers of Gotham. Another theme is identity. The daughter may struggle with her identity as Bruce Wayne's child and also how it relates to Batman. For example, in some fanfictions, she might feel pressured to live up to her father's reputation.
One common theme is redemption. Bruce may travel back in time to correct past mistakes, either his own or those of his family. For example, he might try to save his parents from being murdered in some stories.