One possibility could be that Batman, after facing one too many betrayals in Gotham, decides to take a different path. Maybe the constant struggle against crime with little real change in the city makes him cynical. He could start using his skills and resources to control the underworld instead of fighting it. For example, he might start dictating which criminals can operate and where, creating a new order that is still dark but under his command.
One possible scenario could be that Finn, after being turned into a vampire, struggles with his new identity. He might have to deal with the urge to drink blood while still holding onto his old values. For example, he could try to find alternative ways to satisfy his thirst that don't involve harming humans, like drinking animal blood.
One idea could be that Stiles is turned into a vampire against his will. Maybe he's attacked one night while out investigating something supernatural. As a vampire, he has to struggle with his new urges, like the thirst for blood, while still trying to be the same person his friends know. He might start to see the world in a different light, both literally and metaphorically, as his vampire senses heighten.
One possible story could be that Mimiko is bitten by a mysterious vampire one night while walking alone. She then starts to experience strange cravings and enhanced senses. At first, she's terrified, but as time goes on, she begins to embrace her new vampiric nature.
One possible scenario in this fanfiction could be that Finn's transformation into a vampire brings out a whole new side of his personality. He might struggle with his newfound thirst for blood while still trying to uphold his heroic values. Maybe he teams up with Marceline, who is already a vampire, and she teaches him how to control his urges.
Well, in batman vampire fanfiction, the power dynamics are quite interesting. Vampires usually have superhuman strength, speed, and the ability to hypnotize. Batman, on the other hand, has his intellect, martial arts skills, and his arsenal of gadgets. So seeing how he overcomes the physical superiority of vampires is a unique element. Also, the introduction of vampire lore can bring in new elements like the need for holy water or silver weapons, which changes the typical Batman - fighting - crime scenario.
One unique aspect is the combination of the brooding nature of Batman with the dark allure of vampires. Batman is already a dark character, and adding vampiric elements intensifies that. For example, his ability to move in the shadows can be related to vampire stealth.
If Batman becomes Joker in fanfiction, Gotham would be in chaos. Batman is the symbol of justice and order, while Joker represents chaos and anarchy. Without Batman to protect the city, criminals would run wild. And as the new 'Joker', Batman might use his intelligence and skills in a very different and dangerous way, perhaps creating more harm than good.
If Batman becomes a Lantern in fanfiction, he would gain the power of the Lantern ring. This could enhance his combat abilities even further. He might use the ring's energy constructs in his crime - fighting, creating things like shields or grappling hooks. His detective skills combined with the Lantern powers would make him an even more formidable force in Gotham.
The Joker could still be a major villain. Even with Batman as a god, the Joker might find some twisted way to challenge him. Maybe he'd try to drive Batman to use his god - like powers in a way that goes against his moral code. Ra's al Ghul could also be a villain. He might see Batman's new godhood as a perversion of the natural order and seek to destroy him.