They'd probably be shocked. Zuko's past is full of hardships and they might not have expected all that he's been through.
The gaang would likely have a range of reactions. Aang, being the empathetic Avatar, might feel sorry for Zuko. Katara, who has her own traumas, could see some similarities in Zuko's pain. Sokka, on the other hand, might be more hesitant to fully accept Zuko's past as an excuse for his actions at first, but over time could come to understand better. Overall, they would all be forced to view Zuko in a new light.
Well, they might gain a deeper understanding of Zuko. They could see all the pain and struggle he went through, which might lead to them being more empathetic towards him. Maybe it would even change their relationship dynamics, making them more accepting of Zuko in the group.
The Gaang may also feel guilty in a way. If they see Zuko's attempts to do the right thing in his memories, like when he tried to capture the Avatar in a more honorable way at times, they might regret some of their harsher judgments of him in the past. And this could lead to a closer friendship among them all.
In the 'the gaang kidnaps zuko fanfiction', the Gaang might kidnap Zuko because they've been misinformed. They could have heard false rumors about Zuko planning a major attack on them or on some innocent people. So, they decide to take matters into their own hands and kidnap him to prevent this so - called attack. Once they have him, they start to realize that they may have made a mistake, which could lead to a whole series of events like trying to make amends or finding out who spread the false rumors.
Well, in this kind of fanfiction, the Gaang would likely gain a deeper understanding of Zuko. They might see his past traumas, his family issues, and his long journey of redemption. This could lead to them feeling more sympathetic towards him, and perhaps changing their previous perceptions of him. It could also strengthen their bond as a group, as they share this intimate look into one of their member's past.
Obviously, the main characters would be the Gaang, which includes Aang, Katara, Sokka, Toph, and Zuko himself since he's the one being kidnapped.
Some of them might be excited. They could see new ideas and interpretations of their world that they hadn't thought of before. For instance, if there are new bending techniques in the fanfiction, the benders in the gaang might be eager to try them out in their imagination. Others might be more critical and point out inaccuracies compared to their real - life experiences in the Avatar world.
Some of the gaang members might be very excited. Aang, being the Avatar, would probably be curious to learn from Ursa. He could ask her about the Fire Nation's history and how it relates to the balance of the world.
The Gaang's reaction would be complex. Sokka would probably be on guard but also intrigued. He might start to analyze Azula's motives right away. Toph would be more straightforward. If Azula saved her life directly, she might be more willing to give Azula a chance, but still be ready to fight if things go wrong. Zuko, if he's with the Gaang, would have a really mixed reaction as she is his sister.
Some of their friends from the Fire Nation, like Mai, could be hesitant. She might worry about the implications for the Fire Nation's future and Zuko's role as a leader. However, as time passes and she sees how much Zuko loves Katara and their unborn child, she becomes more accepting. On the other hand, the Water Tribe elders could have mixed reactions. Some might see it as a good sign of unity, while others might be concerned about cultural differences.
They could meet past Air Nomads. These could be great benders or spiritual leaders who can offer wisdom and advice.