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.
Nightwing's age can vary depending on the specific comic storyline and continuity. But generally, he's often depicted as being in his mid to late twenties.
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.
Some Avengers might be excited. Captain America, for example, would probably welcome Nightwing for his sense of justice and fighting skills. Thor might be intrigued by this new addition from another world (in a sense, as Gotham is different from Asgard). However, Hulk might not care much as long as Nightwing doesn't get in his way during a fight. Overall, there would be a mix of curiosity and acceptance.
The 'nightwing origin graphic novel' is significant as it delves deep into the origin story of Nightwing. It shows how Dick Grayson, originally Robin, transitions into Nightwing. This origin helps fans understand his character growth, his motives, and how he becomes an independent hero apart from Batman.
His brothers would likely be very protective. They might immediately go on the offensive against whoever hurt Nightwing. For example, if it was an enemy attack, they would fight back fiercely. They would also be concerned about his well - being and quickly try to assess the extent of his injuries.
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.
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.