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 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.
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 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.
One possible reason could be mind control. Maybe some villain has taken over Superman's mind and made him do it. Another reason might be a fundamental difference in their ideologies that has escalated to the point of no return.
Alfred Pennyworth is quite popular too. He can offer his wisdom and support to Batman, and his interactions with Superman can be both humorous and heartwarming. He's like the glue that holds things together in the Batcave, and his presence can bring a sense of home to the story.
In Batman and Superman fanfiction, 'stranger danger' can be depicted in various ways. For example, a new villain could be introduced who is a stranger to the city and poses a great danger. The heroes would then have to figure out the stranger's motives and powers to stop them. It adds an element of mystery and suspense to the story.
It could be that in the fanfiction, Superman has been corrupted in some way. His values have shifted, and he sees Batman as a threat to his new - found ideology. So, he decides to take Batman down, resulting in the injury. This could lead to a complex story of redemption or further conflict.
The friendship in fanfiction often shows how they overcome their differences. Superman, the idealist, and Batman, the pragmatist, learn from each other. They might start as rivals but gradually realize that together they can achieve more. Fanfictions can also explore their personal lives outside of heroics and how their friendship impacts those aspects.
In fanfiction, Batman and Superman's friendship is often complex. They are two very different heroes. Batman is a brooding, human with no superpowers but great intellect and skills. Superman is an alien with god - like powers. Their friendship can be based on mutual respect for their fight against evil. Sometimes Batman is the one to keep Superman grounded, reminding him of his humanity. And Superman, in turn, can show Batman that there is more to the world than just the dark alleys of Gotham.