A really cool storyline might be a situation where they are both framed for a crime they didn't commit. They have to work together to clear their names while also dealing with their own personal issues. Batman might be suspicious of Green Arrow at first, and vice versa. This would create a lot of tension and drama. Also, a fanfiction where they are transported to an alternate universe and have to find their way back could be exciting. They would face new challenges and enemies that test their abilities in different ways.
One popular theme is the clash of their ideologies. Batman is often portrayed as a dark and brooding figure who works in the shadows, while Arrow is more of a vigilante with a slightly different moral code. Their different approaches to justice can lead to some interesting confrontations in fanfiction. Another theme is team - ups. Writers like to explore what would happen if they joined forces against a common enemy, like a super - powerful villain. And of course, there's the classic battle theme, where fans want to see who would come out on top in a physical fight between the two.
In my opinion, Batman would probably win. Batman has a vast array of high - tech gadgets and is a master of many forms of combat. He's also a brilliant strategist. Green Arrow, while an excellent archer and fighter, doesn't have the same level of gadgetry and has been shown to be a bit more impulsive at times. But it really depends on the circumstances of the fight in the fanfiction.
A cool plot could be that in the fanfiction, there is a meta - human who can manipulate time and space. Green Arrow and Batman get caught in one of his experiments and end up in an alternate dimension where they have to rely on each other's skills to get back home. Also, a plot where Green Arrow's family and Batman's allies are kidnapped by the same criminal organization. They must work together to rescue them all. Additionally, perhaps a plot where Green Arrow and Batman swap identities for a day as part of a bet or a mission gone wrong and hilarity and some deep insights into their characters ensue.
Maybe there's a storyline where they team up against a common enemy. A powerful criminal who uses both high - tech gadgets like Batman's villains and has a dark, serial - killer - like mind like Dexter's prey. They have to combine their skills, Batman's detective work and combat skills with Dexter's forensic knowledge and ability to blend in.
One interesting storyline could be Catwoman stealing a valuable artifact that has a connection to Batman's past. This forces Batman to track her down, but as he does, he discovers that Catwoman has her own reasons for taking it that are more complex than simple theft. Another could be a situation where Catwoman and Batman are forced to team up against a greater threat in Gotham, like a new super - villain who is out to destroy the city. And a third one might be a story where Catwoman tries to frame Batman for a crime he didn't commit, leading to a tense cat - and - mouse chase between them.
One great storyline could be where Arrow and Batman team up to take on a common enemy like Ra's al Ghul. Arrow's skills with the bow and his street - level fighting ability combined with Batman's detective skills and high - tech gadgets would make for an exciting adventure. They could start off as rivals, not fully trusting each other, but as they face the challenges set by Ra's, they learn to work together and respect each other's methods.
One interesting scenario could be when Batman tries to analyze Naruto's chakra system using his detective skills. Another could be Naruto being teleported to Gotham and having to deal with Batman's villains while Batman tries to figure out who he is. And also, a scenario where they team up against a common enemy like an alien invasion in a crossover fanfiction world.
I really like 'Green Arrow in Gotham'. In this fanfiction, Green Arrow finds himself in Gotham City and has to navigate the dark and dangerous world while also dealing with Batman's somewhat cold welcome. It's full of action and great character interactions.
A storyline could involve Nightwing being framed for a crime in Gotham. Batman, believing the evidence at first, tries to bring him in. Nightwing, of course, resists as he is innocent, and this leads to their fight. As the story progresses, they both realize there's a bigger conspiracy at play.
Ra's al Ghul would be a great choice. He has ties to both the Arrow universe and Batman's world. He could be manipulating events in both Star City and Gotham, forcing Arrow and Batman to team up to stop his grand scheme. His immortality and vast resources would pose a huge challenge for them.