Harley Quinn could also be shown as a tragic figure. In the Dark Knight fanfiction, she could be a product of Gotham's corrupt system. Maybe she was failed by the very institutions that were supposed to protect her, which led her to a life of crime. This would add depth to her character and make her more than just a crazy villain.
Another way to portray her is as a wildcard. In the Dark Knight universe, she could be the element that no one can predict. She might switch sides at a moment's notice, depending on who she thinks can offer her the most excitement or power. Her actions could be driven by her need for chaos and her own brand of justice, which is different from both Batman's and the Joker's.
Their relationship could be portrayed as more of a friendship. Instead of the typical toxic relationship, they could be shown as two outcasts who support each other in their own strange ways. For example, Harley helps the Joker with his plans not out of love in a romantic sense, but because she values their friendship.
The Dark Knight's version of the Joker adds an extra layer of darkness to their relationship in fanfiction. Writers might explore how the Joker's chaos affects Harley even more in this darker context. For example, Harley could be torn between her love for the Joker and the realization of the horror he spreads in Gotham.
Obviously, the Joker and Harley Quinn are the most popular. The Joker's chaotic and unpredictable nature makes for great story - telling. He can be the main source of conflict and drama. Harley Quinn, on the other hand, has a complex character. Her love for the Joker despite his abuse, and her own journey of self - discovery are very interesting to explore in fanfiction.
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.
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.
In fanfiction, the Joker and Harley Quinn can have a huge impact on Gotham. Their antics can range from small - scale chaos like random acts of vandalism to large - scale threats like trying to take over key parts of the city. They are often portrayed as a force that the police and Batman constantly struggle to contain.
The male version could be portrayed as having a more brute - force approach. While the female Harley Quinn was known for her acrobatics and agility, the male could be stronger physically. For example, in a fight scene, he might rely more on his strength to overpower opponents rather than the female Harley's nimble dodging.
The relationship can be portrayed as a journey. At first, the Joker and Harley might not know how to be parents. They could be clumsy and make mistakes. But as the baby grows, they start to adapt. The Joker might start to soften a bit, realizing that his actions could affect the baby's future. Harley would be the glue that holds the family together. She could be the one who arranges family dinners, even if it's just pizza in their hideout. The baby could also bring out a competitive side in them, like who can teach the baby the coolest trick or skill.
Batman is typically portrayed as the brooding, justice - seeking vigilante. He is highly intelligent and physically capable. In relation to Harley Quinn, he is often in a position of trying to 'fix' her or at least stop her from causing more chaos. Harley Quinn, on the other hand, is shown as a wild, unpredictable character. She has a flamboyant style and a love - hate relationship with the Joker which also affects how she interacts with Batman.
Harley Quinn's character can be developed by showing her struggle with her identity after the Joker's death. In Arkham Knight fanfiction, she could start to question her loyalty to the Joker's legacy. Maybe she begins to form her own moral code, separate from the chaos the Joker brought.