One common theme is the clash of their different personalities. Batman is dark and brooding, while Iron Man is more flamboyant. Their interactions often explore how they deal with this contrast.
Sure. 'The Dark and the Armored' is a great one. It combines Batman's detective skills with Iron Man's high - tech gadgetry in an interesting way. The story has them team up to face a new super - villain who is a tech - genius and a master of stealth.
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.
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 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 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.