One possible fanfic could involve a battle against a powerful villain. Nightwing might get injured while trying to protect Gotham. Batman then has to step in not only to defeat the villain but also to take care of Nightwing. He could use his advanced medical knowledge and resources in the Batcave to nurse Nightwing back to health.
First, you need to decide on the cause of his injury. It could be a fight, an accident, or something more complex like a magical curse. Then, think about how it affects him. Does it slow him down? Make him question his abilities? Next, consider the other characters' reactions. Will Batman be worried? How about his friends like Barbara Gordon? Finally, write a detailed description of his injury and his journey to recovery.
One example could be a story where Nightwing gets injured during a fight with a powerful villain in Gotham. The author might focus on his struggle to recover, both physically and mentally. Maybe he has to rely on his friends in the Bat - family for support.
A plot idea could be that Nightwing is injured while saving a group of hostages. Batman then has to deal with the criminals who were holding the hostages as well as take care of Nightwing. The story could explore Batman's feelings of guilt for not being there in time to prevent Nightwing's injury.
He might try to reason with kaldur. If Nightwing can make kaldur see that what he's doing is wrong or that there are better ways to achieve his goals, kaldur could let him go. Nightwing is known for his charisma and intelligence in such situations.
He might try to engage Slade in conversation. Nightwing is smart and could be looking for a way to psychologically get an edge over Slade. He could be probing for Slade's motives, hoping to find a way to turn the situation around. He might also be stalling for time, waiting for the right moment to make his move.
Batman is the most likely. He has a strong bond with Nightwing and would do anything to save him. His skills in combat and detective work would be crucial in finding and freeing Nightwing.
Nightwing would initially be defiant. He's a highly trained fighter and detective in his own right. So, he won't cower in front of the Joker. He'll probably try to size up the situation, looking for any weaknesses in his captivity and the Joker's plan.
Batman could be a main character. Since Nightwing was trained by Batman, in a baby Nightwing fanfiction, Batman could be the one taking care of him, teaching him basic skills, and protecting him from the threats of Gotham.
Captain America could be a strong ally for Nightwing. Captain America is a great leader and has a strong sense of justice. Nightwing, coming from Gotham, also has a deep - rooted sense of right and wrong. They could lead the Avengers together in a battle, with Captain America providing the strategic leadership and Nightwing using his agility and combat skills to execute the plans on the ground.