A plot twist could also be that it's all a ruse by Harley Quinn. She might be using her 'love' for Batman as a way to get closer to him and then ultimately betray him. However, as she gets closer to Batman, she starts to really fall for him, and now she has to choose between her original plan and her new - and real - feelings.
Maybe Harley Quinn's love for Batman causes her to turn against the Joker completely. This would be a huge shift as she has been so closely associated with the Joker for a long time. Her newfound love could lead her to try and reform herself to be worthy of Batman's love, and in the process, she might become an unexpected ally for Batman in his fight against Gotham's villains.
A plot twist might be that Harley Quinn has a change of heart not just about the Joker, but also about Gotham's power structure. She decides to help Batman not just against the Joker, but also against some corrupt elements in Gotham that Batman has been trying to expose. So, instead of just being a one - off ally against the Joker, she becomes a long - term partner in cleaning up Gotham.
Imagine a fanfiction where a new super - weapon is being developed in Gotham. Poison Ivy and Harley Quinn get wind of it and decide to steal it, thinking it could be used to further their own goals. Batman, of course, is trying to stop them. But as the story unfolds, they all realize that the weapon is far more dangerous than they initially thought. So, instead of fighting each other, they have to work together to destroy the weapon before it destroys Gotham. This forces them to put aside their differences and form an unlikely alliance.
A possible plot could be that Harley Quinn's sister is an undercover agent sent to infiltrate the criminal underworld of Gotham. She ends up getting involved with Harley and the Joker. As she gets closer to her sister, she realizes that Harley is more than just a crazy villain. She then tries to find a way to get Harley out of the criminal life while also dealing with Batman's suspicions of her true motives.
One possible plot could be that Harley Quinn discovers she's pregnant and tries to hide it from the Joker, fearing his reaction. Meanwhile, Batman somehow gets wind of it and feels a sense of responsibility to protect her, not just for the baby's sake but also because he realizes Harley is in a very vulnerable state.
A possible plot twist is that Fem Harry Potter discovers a magical item that links her to Harley Quinn's world in some way. Maybe it transports her there briefly, and she has to learn to adapt to Harley's Gotham while also bringing some of her Hogwarts magic. This could create a really interesting clash of two very different universes.
One interesting aspect of 'Batman and Harley Quinn Love Fanfiction' is how it reimagines their relationship. In some fanfictions, Harley Quinn's complex character is softened by Batman's influence. It's a unique take as in the original comics their relationship is more of an adversarial one. Fanfiction allows for a different exploration of their personalities and how they could potentially interact on a more emotional and romantic level.
A plot could involve Robin being kidnapped by one of Harley Quinn's old associates who has a vendetta against her. Batman and Harley Quinn then have to work together to rescue Robin. During the rescue mission, Harley Quinn starts to see Batman in a new light and realizes that his way of fighting crime might be more noble than she initially thought. Meanwhile, Robin, while being held captive, manages to outwit some of the captors, setting up an exciting climax when Batman and Harley arrive.
Gotham's perception of Batman could change. Some might see him as being weak for getting involved with a former villain like Harley Quinn. This could lead to a loss of some of the public's trust in Batman. However, if Harley truly reformed and they worked together to make Gotham better, it could also inspire hope among the citizens. They could see that even someone like Harley can change for the better, and that love can conquer even the darkest of pasts.
The plot might involve Harley Quinn helping Batman in a major way to save Gotham. This act of heroism makes Batman see her in a new light. They begin to fall in love and decide to get married. However, the Bat - family might be against this union at first. But as they see how Harley truly loves Batman and is committed to the cause of justice, they slowly come around.
There are multiple challenges in their potential love story. Firstly, Batman's trust issues would play a role. He has been betrayed before and would be hesitant to fully trust Harley. Secondly, Harley's own identity is somewhat tied to her relationship with the Joker and her life as a villain. She would need to completely re - evaluate and reinvent herself to be with Batman. And finally, the public perception in Gotham would be a huge hurdle. The citizens look up to Batman as a hero, and his relationship with a former criminal could cause a lot of unrest and questions about his judgment.