Lex Luthor would be a great villain. He could be plotting to destroy Superman once and for all while also trying to outsmart Batman. His intelligence and resources make him a formidable foe for both heroes.
A cool plot could be that a powerful alien race arrives on Earth and offers a deal to the world leaders. Batman is suspicious of their motives and starts investigating. Superman, on the other hand, is more open - minded at first. This causes a rift between them. As Batman uncovers more evidence of the aliens' true intentions, he has to convince Superman. In the end, they join forces to stop the aliens from taking over the Earth.
Lex Luthor would be a great antagonist. He could play on the differences between Batman and Superman, trying to turn them against each other while he pursues his own evil plans. Maybe he creates a situation where it seems like Superman is a threat to Gotham, causing Batman to be on high alert.
Lex Luthor would be a great choice. He's Superman's long - time nemesis. He could form an alliance with some of Batman's foes like the Joker. Luthor could use his intelligence and resources to create a plan that only Superman and Batman together could stop.
One idea could be that Batman and Superman have to team up to stop a new villain who has the power to manipulate time. This would put their different approaches to justice to the test as they race against the clock.
One idea could be that Superman and Batman have to team up to stop a new supervillain who has the power to manipulate time. This would force them to put aside their differences and work together in a really challenging situation.
Well, in a fanfic about Batman and Superman's friendship and fatherhood, they could be depicted as mentors to their sidekicks in a more fatherly way. Batman with Robin and Superman with Superboy perhaps. Their friendship might be tested as they balance their superhero duties and their newfound father - like roles.
One aspect of a Batman - Superman friendship fanfic could be how they overcome their differences. Batman is a dark, brooding vigilante while Superman is the all - American hero. Their friendship might start from a mutual respect for each other's abilities. For example, in a story, they could team up to fight a common enemy that neither could defeat alone. This would force them to rely on each other and learn about the other's strengths and weaknesses.
One common theme could be the exploration of their complex relationship in a more romantic or sexual context. Another might be the power dynamics between the two very powerful characters.
One common theme is the corruption of power. Maybe Superman's power has gone to his head, and Batman sees the need to stop him at all costs. Another could be a mind - control scenario where Superman is being controlled by an outside force and Batman has no other option.