Obviously, Bruce Wayne (Batman) is a key character. Then there are the members of the Justice League like Superman, Wonder Woman, Flash etc. They all play important roles as they interact with Bruce Wayne.
Well, in this fanfiction, there could be an epic showdown against a common enemy. The Justice League might initially be skeptical of Bruce Wayne's methods, but then they come to respect his strategic mind.
Some members might be shocked. Wonder Woman, for instance, who respects Batman's skills and tenacity, would likely be very disappointed. She might try to persuade him to stay, emphasizing the importance of his presence in the team. Superman, on the other hand, might initially be understanding, as he knows Batman has his own way of doing things. But he would also be concerned about the power vacuum that Batman's departure would create. Aquaman might be more indifferent, thinking that Batman was always an outsider to some extent, with his focus mainly on land - based issues.
Well, there's also Oracle, Barbara Gordon. She sometimes gets involved in the fanfictions related to Young Justice and Bruce Wayne. She can provide technological support and another perspective, given her own experiences and skills. Her relationship with Bruce adds another layer of complexity to the stories.
There's 'Bruce Wayne: The Silent Guardian in Young Justice'. This fanfic focuses on Bruce's behind - the - scenes work in the Young Justice universe. He's constantly looking out for the young heroes, providing resources and strategic advice without them always being aware of his full involvement.
The Flash might initially be in denial. He's used to Batman always having a plan and his death would be a huge shock. He would then turn his speed into a tool for investigation, trying to find out exactly what happened. Green Lantern could feel a sense of loss but also be spurred into action, using his ring to try and prevent future tragedies like Batman's death. He might create constructs in Batman's memory to inspire the team.
Some of them might be amused. They could find the different takes on their characters and stories quite entertaining. For example, Superman might chuckle at a fanfic that has him in a comical situation.
The Justice League as a whole would have a diverse range of reactions. Some members like the Flash would be all for it, seeing it as a fun exploration of Batman. Others like Wonder Woman might use it as a way to understand how the public perceives Batman's role in the League. And then there are those like Aquaman who might just shrug it off unless it directly affects his interests. The fanfiction could also potentially create some internal discussions within the League about how they are all portrayed in the public's imagination.
Some of them might laugh. They would see the creative and sometimes out - there ideas that fans come up with in the fanfiction. For example, if there's a fanfic where Oliver Queen teams up with a really strange character from the Arrowverse, it could be quite humorous to them.
In this fanfiction scenario, Poison Ivy may initially be angry. She might feel betrayed if she had some sort of relationship with either Bruce Wayne or Batman before. She could also be a bit jealous, thinking that Batman has been hiding this huge part of himself from her. However, on the other hand, she could also be impressed by the lengths Bruce goes to protect the city. This new knowledge could lead to a whole new dynamic between her and Batman, with her either becoming an ally or an even more dangerous foe, depending on her motives and the events that unfold in the fanfiction.