Aang would feel a sense of urgency and his connection to Katara would make him even more determined. He would call upon the spirits if necessary to find her. Sokka would be full of fury and his strategic mind would be working overtime to come up with a plan. He would also be very protective of his sister's honor during this time. Toph would be steadfast in her support for the rescue. She might even create some distractions to help the others get closer to Katara. The Fire Nation soldiers who respect Zuko might be confused by his actions, while those who dislike him might see it as an opportunity to bring him down. And Katara would be using her waterbending skills to defend herself and try to escape at every opportunity.
Avatar: The Last Airbender is indeed an original story. It has its own distinct style and narrative that sets it apart. The combination of elements like bending powers, diverse characters, and complex story arcs make it a one-of-a-kind creation.
Definitely not real. It's a fantasy world crafted with unique characters and magical elements that exist only in the realm of imagination and storytelling.