In a Batman joins Darkseid fanfiction, the power dynamic would change drastically. Darkseid is an extremely powerful being. Batman's intelligence and skills could be used by Darkseid for his own evil plans. Batman might be able to influence Darkseid in some ways too, perhaps trying to limit the destruction. However, it's likely that Batman would be constantly conflicted, as his nature is to oppose tyranny, which Darkseid represents.
If Batman were to join Darkseid, it would be a huge shift in the DC universe. Batman is known for his strong moral code and fighting against evil. Joining Darkseid would mean he has to abandon his principles. Maybe he's forced to do it under some mind - control or a desperate situation to save Gotham in a way he thinks only Darkseid can help. But it would also make him a target for all his former allies, like the Justice League.
In such a fanfiction, the story might develop as Batman discovers secrets about Darkseid that he thinks he can use to his advantage. He could be playing a long - game, pretending to be on Darkseid's side while actually planning to bring him down. However, Darkseid is no fool and would likely test Batman's loyalty. Meanwhile, the rest of the DC universe would be in chaos as they try to figure out why Batman has turned and how to stop him if he's truly gone bad.
One possibility is that Batman would bring his detective skills to the Avengers. His ability to analyze a situation and find clues is unrivaled. He could help the Avengers solve mysteries that they might not be able to on their own. For example, if there was a villain leaving behind complex riddles or hidden messages, Batman would be the one to crack them. Also, his martial arts skills would be a great addition to the team's combat capabilities. He could train some of the Avengers in different fighting styles, enhancing their overall performance in battles.
If Batman joins the League of Assassins in fanfiction, he might initially be seen as a powerful asset. His skills in combat, detective work, and strategic thinking could be used to further the League's goals. However, he would also likely be at odds with their more extreme and unethical methods. He might try to reform the League from within, or he could be using his membership as a way to gather intelligence on them for the greater good of Gotham.
Batman would be in a tough spot. Darkseid is extremely powerful. But Batman is not one to give up easily. He might try to analyze Darkseid's powers and find a way to counter them, even in captivity.
There probably is. Given the popularity of both Darkseid and Batman in the DC universe, it's a common and rather dark theme for fanfiction writers to explore. Some might write it to show the extreme power of Darkseid, while others may use it as a starting point for a more complex alternate universe story where Batman's death has far - reaching consequences for other characters.
Batman joining the Dark Side would mean a complete shift in the power dynamics of Gotham. The police force, which has had an uneasy relationship with Batman at times, would be in a state of panic. They would no longer be able to rely on him as an ally, and would have to deal with a much more dangerous vigilante - turned - villain. His knowledge of Gotham's underworld and all its secrets would now be used to his own advantage, rather than to protect the city.
In a fanfic where Batman joins the Joker, it could lead to a really strange and dark alliance. Maybe Batman is trying to understand the Joker's madness from the inside. He might pretend to be on the Joker's side to stop a greater evil that only the Joker seems to know about.
Well, if Darkseid kidnaps Batman in a fanfiction, it could lead to an interesting exploration of Batman's character. He'd be out of his element, in Darkseid's domain. But Batman has a strong will. He might try to understand Darkseid's motives while looking for an opportunity to turn the tables. It could also show how the other characters in the Batman universe react to his disappearance.
In a 'darkseid vs avengers' fanfiction, it could go many ways. Maybe the Avengers' teamwork and diverse powers would give them an edge. For example, Thor's lightning and Hulk's strength could be used in a coordinated attack against Darkseid.
One possible plotline could be that Darkseid is about to destroy Gotham or Earth in a way that Batman has no other option but to kill him. Maybe all of Batman's usual gadgets and allies are useless, and he has to use a kryptonite - like weapon (if it could affect Darkseid) to take him down.