Another plot could involve an alternate universe where Batman and Superman are friends from the start. They grow up together, with Batman helping Superman understand human nature better and Superman teaching Batman about his Kryptonian heritage. However, a threat from another dimension arrives that tests their friendship and forces them to use their combined strengths in ways they never expected.
One interesting plot could be Batman and Superman having to team up against a common enemy that is more powerful than either of them alone. This forces them to put aside their differences and combine their skills.
Lois Lane is often a popular character. In fanfiction, she might play a crucial role in mediating between Batman and Superman or getting involved in their adventures in a more hands - on way, using her investigative journalism skills.
One interesting plot could be Clark and Lois working together to expose a conspiracy in Gotham that involves both Superman and Batman. Maybe they discover that a powerful criminal organization is trying to pit the two heroes against each other for their own gain. They use Lois' investigative skills and Clark's powers to gather evidence and try to bring peace between the two vigilantes.
One main plot point is the ideological clash between Batman and Superman. Batman sees Superman as a potential threat to humanity due to his god - like powers. Superman, on the other hand, is just trying to do good but is often misunderstood. Another point is Lex Luthor's manipulation. He fuels Batman's distrust of Superman and sets them on a collision course. Also, the discovery of Kryptonite by Batman gives him a means to potentially defeat Superman in a fight.
The key characters are Batman, Superman, and Lex Luthor. Batman is the Dark Knight, a vigilante with no superpowers but great detective skills and combat abilities. Superman is the Man of Steel, an alien from Krypton with super strength, speed, and other amazing powers. Lex Luthor is a brilliant but devious billionaire who sees Superman as a threat to his own power and plans to destroy him by pitting him against Batman.
One interesting storyline could be a team - up against a powerful new villain that neither can defeat alone. They have to combine their unique skills, like Superman's super strength and Batman's detective skills.
One interesting aspect could be the exploration of their possessive natures in unique situations. For example, how they might be possessive over their cities or certain people they care about. It can add a new layer of depth to their characters.
One idea could be a story where Batman and Superman have to team up to stop a new villain that has the power to manipulate time. This would force them to put aside their differences and really work together in a way they haven't before.
In some Mpreg fanfictions, there could be a storyline where Batman and Superman have to figure out the genetics of their unborn child. Given their different origins - one being a Kryptonian and the other a human with no super - powers originally - it would be fascinating to see how their child might inherit or combine their abilities. There could also be a plot where they have to deal with time - traveling villains who try to prevent the birth of their child for some evil purpose.
One interesting story could be where Superman's obsession leads him to constantly protect Batman in a very overzealous way. He might be there at every crime scene Batman shows up at, much to Batman's annoyance at first but then they gradually develop a deeper understanding. Another could be a story set in an alternate universe where Superman's obsession is due to some sort of mind - control and Batman has to figure out how to free him from it while also dealing with his overly affectionate and protective behavior.
In some fanfiction, Superman might carry Batman while they are on a mission to a far - off planet. Batman, being a normal human (albeit a highly trained one), needs Superman's flight ability to reach the destination quickly. This could lead to some interesting dialogues between them as they travel through space, with Batman analyzing the situation and Superman just focused on getting there.