In many 'Batman Beyond' fanfictions where Dana finds out, it could be about her finding out Bruce Wayne is Batman. Maybe she stumbles upon some evidence in the Batcave or notices some similarities in Terry's behavior to Bruce. For example, she might notice Terry's fighting style is similar to what she's heard about Batman's. It could also be that she discovers some secret technology related to Batman that leads her to the truth.
She could find out some secret plan that Bruce and Terry are working on. This could put her in danger as she now knows something she wasn't supposed to. She may have to be protected by Batman, which would be an interesting turn of events.
One great fanfiction could be where Terry and Dana go on an adventure together outside of Gotham. They might encounter some new villains or find a mysterious place. It could explore their relationship deeper, like how Dana reacts to Terry's double life as Batman.
Their relationship is appealing because it's a normal relationship in a world full of superheroes and villains. It shows that even Batman has a personal life. In fanfiction, we can see how they support each other through different situations, like Terry protecting Dana from the threats of his enemies.
One interesting plot point could be how they combine their lives. Since Terry has the double life as Batman, Dana might have to adjust to sharing her husband with the city. Another could be them starting a family and how they protect their children from the dangers of Neo - Gotham.
In such a fanfiction, it could be a really heartwarming story. Maybe Terry finally decides to put his dangerous Batman life aside a bit more for Dana. They could have a small, intimate wedding with their closest friends and family from the Batman Beyond world. The ceremony might be held in a beautiful, futuristic setting, like on a rooftop overlooking Neo - Gotham at sunset.
Well, he might be initially confused. Batman is so focused on his mission in Gotham that fanfiction about a character like Slade might seem very strange to him. He could start investigating if he thought it had any connection to real - world threats or if it was somehow influencing public perception in a negative way.
One example could be 'Batman and Terry: The Protective Bond' where Batman constantly saves Terry from dangerous situations and also mentors him to become a better hero. Another might be 'Protecting Terry: Batman's New Mission' which focuses on Batman's sole mission of keeping Terry safe in a Gotham filled with new threats.
One possible consequence is that Batman's loved ones would be in great danger. His enemies could target them to get revenge on Batman. Also, the public's perception of Batman might change. Some might see him as a hero who has been hiding his true self to protect them, while others could think he has been deceiving them all along.
If Joker finds out Batman's identity in fanfiction, it could lead to a total breakdown of Batman's world. Joker might target Bruce Wayne's loved ones directly. He could expose Batman's identity to the public, causing chaos in Gotham as the people lose their faith in the symbol of Batman. And he would likely use this knowledge to create the most elaborate and cruel traps for Batman, knowing his true self.