Well, a cool crossover idea in the fanfiction could be Naruto teaming up with Batman. Naruto's positive and determined attitude could influence Batman's rather brooding nature. In a fight, Naruto could use his Rasengan against the Arkham Knight's high - tech weaponry. And his shadow clone jutsu would be great for confusing the enemies in Gotham's complex alleys and rooftops.
In a Naruto - Batman: Arkham Knight fanfiction, a possible crossover could be that Naruto gets transported to Gotham. He might be initially confused by the high - tech environment but quickly adapt. His chakra could be seen as a new kind of power in Gotham. He could learn from Batman's detective skills and in turn teach Batman some ninja techniques. This would create a really unique dynamic between the two characters.
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.
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.
A possible crossover could involve the settings. The Hidden Villages in Naruto could be the backdrop for Moon Knight's adventures. Picture Moon Knight in Konoha, dealing with the ninja politics and perhaps even learning some ninja techniques. He could team up with Naruto and the other ninjas to face a common enemy, like a new villain that combines the dark magic from Moon Knight's world with the ninja arts of Naruto's world.
A crossover might involve Sasuke from Naruto in the Vampire Knight universe. Sasuke's search for power could be paralleled with the vampires' thirst for blood or power in their own world. He could encounter the vampire hunters and perhaps form an unlikely alliance with them, seeing as he has his own vendetta against those he deems as powerful enemies. The idea of Sasuke using his Sharingan in a world full of vampires and their unique abilities would make for an exciting story.
When Naruto is reincarnated as a devil in the DxD world, it's quite an engaging concept. He has to deal with the social and power structures of the devil society while still retaining some of his ninja traits. This leads to him using his ninja skills in unexpected ways within the context of the DxD world, like using his transformation jutsu to deceive the devils during their political games.
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.
One interesting plot idea could be a fanfiction where the Joker somehow comes back to life in Arkham Knight. Maybe he was only in a coma and wakes up with a new, even more deranged plan to take over Gotham. He could start by manipulating the inmates in Arkham again, creating chaos from within the asylum.
In this fanfiction, it could be interesting if Catwoman discovers a secret about the Arkham Knight that Batman has overlooked. She could use this knowledge to her advantage, either to make a deal with the Arkham Knight or to help Batman. For example, she might find out that the Arkham Knight has a weakness related to a certain location in Gotham that was important to his past. Catwoman could then lead Batman there to take down the Arkham Knight.
There are fanfictions that explore Poison Ivy's backstory in the Arkham Knight world more deeply. For example, a story might focus on her early days and how she came to have such a strong connection with plants. This can add a lot of depth to her character in the context of the game's lore.
There's a fanfic called 'Arkham Knight: Riddler's New Game'. This one is really interesting as it puts the Riddler in a situation where he has to team up with Batman, albeit unwillingly, to stop a greater threat in Arkham City. The dynamic between the two is explored in a whole new way, with the Riddler's riddles becoming more of a tool for cooperation rather than just a means of taunting Batman.