Well, a really cool storyline might be that in the all - female universe, Harley Quinn discovers a hidden society of female superheroes. At first, they're suspicious of her because of her villainous past, but she convinces them that she wants to change. Together, they fight against a new threat that is trying to destroy both the villain and hero worlds. It could involve Harley using her unique skills and the female superheroes using their powers in a combined effort. And there could be some great character development along the way as Harley tries to fit into this new world of heroes.
One possible storyline could be Harley Quinn adjusting to the idea of motherhood while still dealing with her chaotic life. Maybe she's trying to figure out how to raise a child in a world full of villains and heroes. Another could be her relationship with the father of the baby, whether it's the Joker or someone else, and how that dynamic changes during the pregnancy.
Harley Quinn is the star, of course. Then there's Huntress, who in the all - female universe might team up with Harley more often. Huntress' skills with weapons and her sense of justice could contrast with Harley's more chaotic nature in interesting ways. Another popular character is Zatanna. Her magic can add a whole new dimension to the stories. In some fanfictions, she uses her magic to help Harley on her journey of self - discovery or to fight against other female villains. There are also female versions of Batman's rogues gallery members that are quite popular in these fanfictions.
One interesting storyline could be Harley Quinn trying to break free from the Joker's control. In fanfiction, she might start to realize his true nature of using her and decides to rebel. This could lead to a power struggle between them.
One interesting storyline could be them going on a heist together. They use Poison Ivy's plant powers to create distractions and Harley Quinn's acrobatic skills and unpredictability to get past security. Another could be a story where they rescue each other from the clutches of a common enemy. For example, if the Joker tries to harm Harley, Poison Ivy uses her vines to snatch her away. And they could also have a story where they go on a journey to find a rare plant that has the power to make Harley immune to all toxins, which would be very useful in their dangerous Gotham lives.
A third storyline could be Harley Quinn becoming a vigilante of her own kind. Tired of the chaos and destruction caused by the Joker and other villains, she decides to use her skills and knowledge to fight crime in her own way. She might not be as morally upright as Batman, but she has her own code. She could target criminals who are preying on the weak, and in the process, have run - ins with both the police and the traditional superheroes.
Another could be a love triangle of sorts. In the fanfiction, Poison Ivy might be jealous of Harley Quinn's growing friendship with Batman. Harley is caught in the middle, torn between her loyalty to Ivy and her newfound respect for Batman. This creates a lot of tension and interesting character dynamics.
One possible storyline could be Fem Harry getting inspired by Harley Quinn's chaotic and unpredictable nature. She might start to break the rules at Hogwarts in a more fun - loving way, like Harley does in Gotham. For example, she could play pranks on the teachers that are more elaborate and wild. Another storyline could involve Fem Harry having a split - personality of sorts, where the Harley - inspired side comes out at certain times, leading to some interesting interactions with her friends and enemies. Maybe she even forms a little 'gang' of her own within Hogwarts, similar to Harley's associations in Gotham.
One popular storyline is their adventures in Gotham City together. They might be causing chaos against the villains who oppose them or even teaming up to outwit Batman. Another could be their relationship development, like how they support each other through tough times. For example, in some fanfictions, Poison Ivy uses her plant powers to protect Harley Quinn when she gets in over her head in a fight with some of the Joker's goons.
A third popular type of story could involve the male reader being a psychologist assigned to Harley Quinn's case. Through their sessions, they develop a deep connection. The male reader tries to help Harley break free from her past traumas and her relationship with the Joker. This storyline often delves into Harley's complex character and her journey towards redemption.
One interesting Harley Quinn fanfiction could be about her teaming up with other anti - heroes to take on a new supervillain in Gotham. It might explore her complex relationships in a different light.