One possible reason could be ideological differences. Batman has a very different approach to justice compared to some of the other members. He is more about the streets and dealing with crime on a very personal and gritty level. The Justice League often deals with larger - scale, more cosmic threats. Batman might feel that his methods are being overshadowed or not given enough consideration within the League. Another reason could be a personal crisis. Maybe something in his personal life, like a threat to his identity as Bruce Wayne or a new development in Gotham that requires his full attention, makes him decide to step away from the Justice League.
Maybe he feels betrayed. In fanfiction, there could be a situation where his fellow Justice League members keep secrets from him. For instance, Superman could be hiding something about his true powers or his origin that could potentially be dangerous. Batman, being the detective he is, values truth and transparency, and such secrets might make him feel that he can no longer trust his teammates and thus quit.
One reason could be a moral disagreement. Batman has a very strict moral code. If the Justice League were to engage in actions that he considered too extreme or unethical, he might quit. For example, if they started using excessive force on villains without proper trial. Another reason could be burnout. Constantly fighting crime and dealing with the politics within the Justice League could take a toll on him. He might feel that he needs to step away to regain his sanity and focus on protecting Gotham in his own way.
In many Batman and Robin fanfictions where Robin is injured, it often leads to Batman becoming more determined to catch the villain. For example, in some stories, Robin gets injured during a fight with a new, powerful enemy in Gotham. Batman then uses his detective skills to track down the bad guy while also taking care of Robin. He might call in Alfred for help with Robin's injuries. This kind of situation shows the deep bond between Batman and Robin and how they rely on each other in tough times.
The Penguin could be a great addition. His wacky and devious schemes always make for an interesting story. Also, Catwoman. Her complex relationship with Batman adds a layer of intrigue. And Oracle, who can provide valuable information and support from afar.
One interesting storyline could be Robin growing up and struggling to step out of Batman's shadow. He wants to prove himself as an independent hero while still respecting Batman's teachings.
There is no love story between them. Batman is more like a father figure or a strict mentor to Robin, guiding him in the fight against crime in Gotham City.
In the established Batman lore, a romantic relationship between Batman and Robin is not a part of the narrative. Batman's focus is on protecting Gotham City, and Robin is his sidekick. Their relationship is more about teamwork and the传承 of Batman's ideals. It's about passing on the skills and the sense of justice from Batman to Robin, not a love story.
In the original Batman and Robin concept, their focus is mainly on fighting crime and upholding justice in Gotham. However, in gay Batman and Robin fanfic, while they may still fight crime, the relationship between them becomes a central plot point. Their romantic or sexual connection might influence their decisions during battles, or how they approach other characters. For instance, they might be more cautious not to put each other in too much danger because of their love for each other. Also, the fanfic may explore different aspects of their personalities that are related to their relationship, like jealousy or possessiveness, which are not present in the original concept.