One idea could be a misunderstanding that leads to a battle. Maybe some misinformation makes the Batfamily think Young Justice is involved in something illegal or dangerous. For example, a new villain frames Young Justice by using their tech to carry out crimes. The Batfamily, being the protectors of Gotham, jumps into action without fully investigating.
Tim Drake from the Batfamily might be likely. He's highly intelligent and sometimes over - thinks situations. If he discovers some unusual activity related to Young Justice that he misinterprets, he could be the one to start the ball rolling on a conflict. For example, if he sees some new Young Justice members using untested tech that he thinks could be dangerous, he might take preemptive action against them.
Well, in such a fanfiction, there could be a lot of interesting scenarios. Maybe Batman would have to deal with the different leadership styles of the Justice League while trying to keep his family in line. The Batfamily members could show off their unique skills to the League members, like Robin's acrobatics or Batgirl's hacking skills.
Well, there could be a lot of interesting things. Maybe the Justice League members would be surprised by the Batfamily's unique skills and tactics. For example, Batman's detective skills might impress Superman. They could team up to fight a common enemy in Gotham City. The Flash might be in awe of Robin's acrobatic abilities.
Well, there could be epic battles. The Justice League's powerful members like Superman and Wonder Woman might be initially shocked by the Batfamily's gritty and unorthodox methods. Maybe Batman has to mediate between his family and the League to avoid misunderstandings.
One possible storyline could be a joint mission against a powerful new villain. The Batfamily's detective skills combined with the Justice League's raw power would be a great combination. Another could be a sort of 'cultural exchange' where the League members try to understand the Batfamily's no - kill rule and the family tries to adapt to the League's more open - ended approach to heroism.
Obviously, Batman and his family like Robin, Batgirl would be main characters from the Batfamily side. And from the Justice League, Superman, Wonder Woman, Flash etc. would be the main characters. They are the most well - known members of their respective groups.
A possible plot could involve a member of the Batfamily getting kidnapped and the Justice League helping to rescue them. During the rescue, they discover a secret weapon or technology that the villains were planning to use against the world, and they have to work together to stop it.
Batman, for sure. He has such a complex relationship with the Justice League already. Meeting his family in this context would add another layer to his character. He's the bridge between the two groups.
Batman and Superman would definitely have interesting interactions. Batman's more grounded, detective - like approach contrasted with Superman's super - powered idealism could lead to some great dialogue and moments of conflict and resolution.