The Batman Arkham games generally follow Batman's fight against Gotham's villains. He battles the likes of Joker, Scarecrow, and others. In Arkham Asylum, the inmates take over the asylum. Batman has to fight his way through and deal with Joker's various schemes. In Arkham City, a large part of Gotham is turned into a prison, and Batman has to survive in this dangerous place while trying to stop Hugo Strange and other threats.
The presence of the Arkham Knight in Arkham Knight game is a major plot point. His vendetta against Batman adds a new layer of conflict. Also, the role of Scarecrow cannot be ignored. He spreads fear throughout Gotham, which is a central theme in the series. In Arkham City, the mystery behind Hugo Strange's experiments and his control over the inmates is an important part of the plot. And Batman's relationships with characters like Catwoman also play into the overall story, with their on - again, off - again alliances.
The order is as follows. 'Batman: Arkham Origins' is first as it sets the stage for Batman's development and shows some of his early encounters. 'Arkham Asylum' is next. It's a very important part of the story as it delves into the chaos within Arkham. 'Arkham City' then takes the story further by presenting a new, more dangerous situation in a large part of Gotham. And 'Arkham Knight' is the conclusion, where we see the culmination of many story elements, including Batman's final battles and the resolution of certain character arcs.
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.
In story order, they are 'Arkham Origins' as the start, then 'Arkham Asylum', 'Arkham City', and finally 'Arkham Knight'. This sequence follows the development of Batman's story throughout the series.
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.