One possible plot in this fanfiction could be that Batman is forced to join the Justice League after a series of events in Gotham that are linked to a larger, global threat. He starts off as an outsider within the team, not really fitting in with their more 'flashy' ways of doing things. However, his strategic mind and combat skills soon prove invaluable. He could also have some sort of personal arc where he learns to rely on others more, which is a big change for him as he's usually a lone wolf in Gotham.
Well, it could be about Batman initially being hesitant to fully join the Justice League. Maybe he has trust issues with some of the members at first. Then, he gradually starts to work with them on a big threat that requires all their skills combined, like an alien invasion or a powerful super - villain that's too much for any one hero to handle alone.
Well, a plot twist could be Batman's technology being hacked by an unknown enemy. Since he is known for his high - tech gadgets and strategies, if his systems were compromised, it would put the whole Justice League in jeopardy. Maybe the hack reveals some of Batman's deepest secrets, which could either cause a rift within the League or bring them closer together as they deal with the fallout. Another idea is that Batman discovers a long - lost relative who has ties to one of the Justice League's main enemies. This would create a moral dilemma for Batman and add a whole new layer of complexity to the story.
One reason could be Batman's extreme independence. He's used to operating on his own terms in Gotham. He might see the Justice League's group dynamic as restrictive and interfering with his unique brand of justice. For example, he has his own way of interrogating criminals which might not be acceptable in the more 'by - the - book' Justice League environment.
One possible plot could be that Danny Phantom's ghostly abilities are detected by the Justice League. They initially view him as a threat but then realize he can be an asset. Danny could help them with foes that have intangible or otherworldly powers. For example, against an enemy that can phase through walls or possess people, Danny's experience dealing with ghosts would come in handy.
Well, it could be that Batman gets caught in a powerful explosion during a fight against a super - powered foe. His suit is damaged, and he suffers from severe burns and internal injuries. The Justice League is then faced with the challenge of getting him medical help while also preventing the villain from achieving their evil goals. They might have to split up, with some members protecting Batman and others going after the bad guy.
Well, it could be about the Justice League traveling to the future where Batman Beyond operates. Maybe they need his help to fight a new threat that has some connection to their past villains. For example, a villain from the Justice League's past could have somehow influenced events in the future and they need Batman Beyond's knowledge of the future tech and his unique fighting style to stop it.
One possible plot could be that in the future setting of Batman Beyond, an old threat from the Justice League's past resurfaces. Terry McGinnis as Batman Beyond teams up with the original Justice League members who have come out of retirement. They have to combine their old - school heroics with Terry's high - tech gadgets to defeat the villain.
Obviously, Batman would be one of the main characters. And of course, the other members of the Justice League like Superman, Wonder Woman, Flash, Green Lantern, etc. would also be important. There might also be some villains that are central to the story, such as Lex Luthor who could be plotting against the newly - formed alliance of Batman and the Justice League.
In fanfiction, Shazam joining the Justice League could open up a world of new storylines. His relationship with other members could be explored. He might have friendly rivalries with some, like Green Lantern. His magic - based powers could also introduce a new element to the League's fight against threats that are more magically inclined, such as dark sorcerers or demons.
One possibility is that Naruto's unique ninja skills would add a new dimension to the Justice League's combat capabilities. His shadow clone jutsu could be used for various strategic purposes, like scouting or creating diversions. His rasengan could also be a powerful offensive weapon against super - villains. Also, Naruto's strong sense of justice and his never - give - up attitude would inspire the other members of the Justice League.
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.