Love is also a theme that pops up. Not always in a romantic way, but sometimes the OC might have a platonic love for Harley, seeing her as someone who needs protection or support. Or in some cases, it could be a full - blown romantic relationship where they have to overcome the obstacles of Harley's past and her reputation in Gotham.
One common theme is redemption. Often, the OC might be involved in trying to help Harley find a new path, away from her villainous ways. For example, in some fics, the OC could be a hero - type character who believes in Harley's potential for good.
Another theme is friendship. Despite their differences, Harley and the OC form a bond. It could start as a reluctant partnership but develop into a real friendship over time. Like in some fanfictions where they go through tough situations together and learn to trust each other.
One common theme is friendship. Often, the female oc starts as a stranger to Harley Quinn and they gradually become friends. They support each other through various challenges in the Gotham underworld.
Power dynamics is another theme. Given Harley Quinn's complex relationship with power, especially in relation to the Joker, the male oc can bring a new element to this. Maybe he has his own power struggle within the DC underworld, and his relationship with Harley Quinn either complicates or simplifies that struggle. It could also involve themes of loyalty and betrayal, as in the world of DC, alliances can be fickle.
Another theme is chaos and adventure. Since Harley Quinn is often associated with mayhem in Gotham, the OC gets dragged into her wild adventures. They might face off against other villains or try to outwit the Batman together, which makes for exciting reading.
One common theme is identity. The oc, being Harley Quinn's child, has to figure out who they are. Are they going to follow in their mother's footsteps or forge their own path? Another theme is family. Even though Harley has her own quirks, the oc might still have a strong bond with her or struggle with the idea of family due to Harley's lifestyle.
Physical injury and recovery is also a common theme. Harley Quinn getting injured in battles or dangerous situations and then having to heal both physically and mentally, which makes for interesting storytelling in 'harley quinn hurt fanfiction'.
A theme that frequently shows up is the idea of family. Harley Quinn, who has had a rather chaotic family life herself, tries to create a better family for the baby. Also, the theme of growth is there. As she takes care of the baby, she grows as a person, learning things like patience which she didn't have much of before.
One common theme is her relationship with the Joker. Many fanfictions explore the toxic and complex nature of their relationship. Another theme is her friendship with Poison Ivy, which is often portrayed as a strong and supportive bond. Also, her transformation from a sidekick to a more independent character is a recurring theme.
A major theme is the chaos factor. Harley Quinn is known for her chaotic behavior, and in male Harley Quinn fanfiction, this chaos is often explored in different ways. It could be his actions causing mayhem in Gotham or his internal mental chaos. Also, redemption is sometimes a theme. The idea that this male Harley Quinn might be trying to break free from his past misdeeds or a bad influence.
One common theme is transformation. Bella often goes through a significant change to become like Harley Quinn, both in appearance and personality.