Lex Luthor could be a likely villain. He's always devising plans to take down the Justice League, and this time he might have come up with a scheme that almost succeeds, until Batman steps in. For instance, he could create a super - weapon that targets the unique powers of each Justice League member.
His relationships with the other members of the Justice League can be explored further. For instance, while saving them, he might have deep conversations with Superman about power and responsibility. This could lead to a change in how he views Superman and also in how he approaches his own vigilantism.
Darkseid is another possible villain. He is extremely powerful. He could send his minions to attack the Justice League first, weakening them, and then use some sort of magic or technology to trap them. Batman would then have to find a way to free the League from Darkseid's clutches, perhaps by finding a weakness in Darkseid's power source.
The plot could involve Batman saving the Justice League from a situation where they are physically trapped. Maybe they are in some sort of energy - based prison. Batman, with his detective skills, would first figure out how the prison works. Then, he'd use his gadgets like his grappling hook and batarangs to break through the prison's defenses and free his comrades.
Well, in this fanfic, perhaps the Justice League has been poisoned or mind - controlled. Batman, being the resourceful hero he is, might first analyze the situation carefully. He could then track down the source of the problem, whether it's a new super - villain or an old enemy with a new trick. He'd likely use his Bat - computer to find a cure or counter - measure and then fight his way through any minions to administer it to the League members, saving them from certain doom.
It could be Lex Luthor. He's always been a big threat to the Justice League and would be a likely choice as the main antagonist in a story where Batman has to save the League.
One plot idea could be that Batman discovers a hidden threat to the Justice League that even their superpowers can't detect easily. Maybe it's a new type of mind - controlling technology. He uses his detective skills to find the source and then devises a plan to free his teammates from its influence.
Batman's sacrifice would likely have a huge impact on the Justice League. It could make them more determined to uphold justice in his memory. They might also become more cautious as they've lost a great strategist.
Well, in fanfiction, absolutely. Fanfiction writers often like to explore different aspects of well - known characters. Batman is no exception. He could be singing a lullaby to a scared child in Gotham, or perhaps he has a secret passion for opera and belts out arias in his Batcave when he thinks no one is listening. The possibilities are endless in the creative world of fanfiction.
In a fanfiction like this, the gun could be a symbol of the danger that the Justice League, especially Batman, constantly face. Deadman, being a supernatural element, might be trying to communicate something about the gun's origin or the person wielding it. Batman, with his detective skills, would start investigating while the rest of the Justice League deals with the immediate threat of the gun - related situation.