The Arkham Knight himself. His backstory and motives are already quite complex, and in a Knightfall scenario, there's so much more to explore. He could be on a journey of self - discovery or redemption.
One idea could be exploring how the Knightfall event affects Batman's relationships with his allies in the Arkham Knight universe. Maybe some of them start to question his methods more deeply.
Batman himself is very likely to be the focus. His actions and decisions during the aftermath would have a huge impact on Gotham. Also, Robin could be a central character, especially if the story is about the future of Batman's legacy. He might be stepping up more in Batman's absence or working closely with him to rebuild the city.
Batman is obviously a very popular character in the fanfiction. He is the central figure in the Arkham Knight story, and writers often explore different aspects of his character, like his detective skills or his relationships with other characters.
The Joker, despite not being a central character in 'Batman Assault on Arkham', is still a very popular focus. His chaos - loving personality and his influence on Harley Quinn and other villains can be the center of many fanfictions. Additionally, characters like Bane, with his brute strength and intelligence, can be interesting to write about, especially if exploring his rivalry with Batman in the context of the Arkham assault.
Yuki is also a great choice. Her dual identity as a human raised among vampires gives a lot to work with. You could write about her trying to find her true place in the world. For instance, she might start to question whether she really belongs with the vampires or if she should try to fully embrace her human side. She could also have new relationships with other characters that further explore her identity.
Hush could be a great new villain. He has a personal vendetta against Bruce Wayne, and his skills in disguise and manipulation would make him a formidable foe for Batman. He could be plotting to expose Batman's identity and take over Wayne Enterprises.
One interesting story could be about Batman's internal struggle with the darker side of Gotham while facing the Arkham Knight. It might explore how he overcomes his doubts and fears in a more personal way than in the game.
Ruby. She has a very open - minded and empathetic nature. She would likely be the first to try and reach out to the Arkham Knight, believing that there is good in everyone. She might see his skills and think that, if redirected, he could be a great asset in fighting the Grimm.
The side stories that explore Gotham's underbelly are quite engaging. These tales often involve Batman helping the ordinary people of Gotham who are caught in the crossfire of the city's chaos. They show a different side of Batman, not just as a crime - fighter against super - villains, but also as a protector of the common folk. There are also stories that focus on the Batmobile, which is an iconic part of the Arkham Knight experience. It showcases how Batman uses this powerful vehicle in his fight against crime in Gotham City.
In many fanfictions, Jason saving Batman in 'Batman Arkham Knight' often shows a new side of their complex relationship. It could be a moment of redemption for Jason. Maybe he realizes the true meaning of Batman's mission and decides to put aside their differences. This scenario allows for deep character exploration.