One possible aspect of a Batman and Harley fanfic in the Arkham universe could be their complex relationship. Batman is always trying to uphold justice, while Harley is often caught between her love for the Joker and her own sense of right and wrong. In a fanfic, the author might explore how Batman could potentially save Harley from her self - destructive path. For example, Batman could use his detective skills to show Harley the truth about the Joker's abuse towards her.
One of the best moments could be when Batman manages to outwit Harley in a battle of wits. He uses his knowledge of her psychology to predict her moves. For instance, if Harley tries to set a trap using her knowledge of Arkham's layout, Batman quickly figures it out and turns the tables on her.
Well, there's a fanfic where Harley tries to escape Arkham City and Batman is the one who has to stop her. But instead of the usual chase, they end up having some deep conversations about her relationship with the Joker. It really delves into their characters and the dark and gritty world of Arkham City. It's called 'Harley's Escape and the Dark Knight'. It's an interesting read as it shows a different side of both characters.
One popular theme is Harley's redemption. Many fanfictions explore how the environment of Arkham City could be a catalyst for Harley to break away from the Joker's influence. For example, in some stories, Batman helps her see the error of her ways.
One possible fanfic could be centered around Batman's encounters with Poison Ivy within the Arkham universe. Maybe it could explore their complex relationship, with Batman constantly trying to stop Ivy's environmental extremism while also seeing the good in her intentions at times. For example, Ivy might be trying to protect a particular area in Arkham City that she believes is crucial for nature, and Batman has to find a way to balance the law and her motives.
The Harley Quinn DLC story in Batman Arkham City often focuses on Harley's own adventures and misadventures within Arkham City. It shows her loyalty to the Joker and her attempts to carry out his plans in her own chaotic way.
It enhances the series by adding more content. Simple as that. More stories mean more gameplay time and more things to discover about the Arkham world.
A plot idea could be that Poison Ivy creates a new type of plant - based virus in Arkham that only affects humans who are harming the environment. Batman has to find a way to stop the virus from spreading while also dealing with Ivy's strong beliefs. Another idea is that Ivy discovers a rare plant in Arkham that she believes can save the planet, but it's in a highly guarded and dangerous area. Batman and Ivy might have to work together to retrieve it.
One common theme is Harley Quinn's relationship with the Joker. It could be about her loyalty to him, or her struggle to break free from his influence in the context of Arkham City. Another theme is her interactions with Batman. Maybe she's trying to outwit him or form an unexpected alliance.