What are some interesting plot ideas for a Batman Avengers crossover fanfiction?

One idea could be Batman using his detective skills to uncover a hidden threat that the Avengers initially overlook. For example, he might notice some small, seemingly insignificant details during a battle scene that lead him to a much larger conspiracy.

A plot could involve the Avengers trying to understand the Flash's powers. Tony Stark might be especially intrigued and try to create technology to mimic the speed force. Meanwhile, the Flash could be in awe of the Avengers' different abilities and learn new ways to use his speed from them. For example, he could learn combat strategies from Captain America or how to better control his powers from Doctor Strange. And then they all have to face a threat that only their combined powers can defeat, like a cosmic entity that is draining the life force of both their universes.

One idea could be that the Eternals' powers are needed to defeat a new, extremely powerful villain that the Avengers alone can't handle. For example, a cosmic entity that can manipulate time and space. The Eternals' long - lived knowledge and unique abilities would be crucial in formulating a battle plan.

Well, perhaps in the fanfiction, there could be a cultural exchange of sorts. The Eternals could introduce the Avengers to their long - lived and different ways of life. This might lead to some interesting character development, like Thor learning new forms of combat from an Eternal warrior. Also, the discovery of a hidden connection between the two groups, such as a shared ancestry in some ancient, forgotten time, could be a great plot point.

Maybe the Avengers need the help of the witches from 'The Originals' to reverse a spell that an enemy has cast on Earth. Klaus and Loki could have some interesting interactions as two complex anti - heroes. The witches could use their magic to enhance the Avengers' weapons or powers in unique ways.

One idea could be a crossover with the Doctor Who universe. The Avengers could team up with the Doctor to fight a common enemy that threatens both their universes. Maybe Thanos somehow gets access to Time Lord technology and the combined forces have to figure out how to stop him from using it to rewrite all of reality.

A cool plot could be a race against time. There's a threat that will destroy the world in a matter of days. The Avengers and Defenders initially clash over how to handle it, but then realize they need to combine their resources. For example, Doctor Strange from the Defenders could use his magic to enhance Iron Man's technology for a more powerful weapon against the enemy.

One idea could be that Daredevil's enhanced senses are needed to track a villain who has a cloaking device that the Avengers' technology can't detect. Another could be Daredevil getting caught in the middle of an Avengers - villain battle in Hell's Kitchen and having to team up with them to protect his neighborhood. Or perhaps Daredevil's legal knowledge helps the Avengers deal with the political fallout of one of their big battles.

One idea could be Deadpool trying to join the Avengers in his own wacky way. He might show up unannounced at the Avengers Tower, causing chaos and confusion among the team members. Another plot could involve Deadpool being hired by a villain to disrupt the Avengers, but then he has a change of heart halfway through. Or perhaps Deadpool accidentally travels to an alternate universe where the Avengers are very different, and he has to find a way to get back while also dealing with this strange new team.

One idea could be that the Avengers are somehow transported to the MHA universe. They have to deal with quirks while also trying to find a way back home. Maybe they team up with the students at UA to fight a common villain who has a power that combines both advanced technology and a powerful quirk.