Aang would be very happy and supportive. He has always been a friend to both Zuko and Katara, and he would see their union and the upcoming baby as a positive step towards more harmony in the world. Sokka might be a bit overprotective at first, especially towards Katara. But eventually, he would come around and be excited about being an uncle. Toph would probably make some sarcastic but also very endearing comments about the whole situation.
They would likely have a range of reactions. Yang would probably be impressed by the physical strength and training of some of the soldiers. The RWBY team as a whole would have to grapple with the idea of a military that doesn't rely on Dust or Aura. They might see the Earth military's technology as both a great advantage and a potential danger. If they were to react in a story, it could lead to some interesting crossovers where they try to learn from the Earth military or vice versa.
Some Star Wars characters might be quite amused by Earth fanfiction. For example, Han Solo would probably find the wild and creative ideas in the fanfiction hilarious. He'd chuckle at the strange interpretations of his character and the out - of - this - galaxy concepts that Earth fans come up with.
Some characters might be very intrigued. For example, Albedo, with his scientific mind, would likely analyze the concepts in the fanfiction related to Earth. He'd be interested in how Earth is depicted, its cultures, and technologies. He might even try to find similarities with Teyvat in terms of elemental powers or social structures.
Earth would likely have a mixed reaction. The scientific community would be fascinated by the Clone Troopers' genetic makeup and advanced weaponry. Civilians might be scared, thinking it's an alien invasion. However, some groups, like military enthusiasts, could see them as allies and want to cooperate. There would also be a lot of speculation about their purpose and where they came from. If the Clone Troopers came in peace, there could be a slow process of integration and cultural exchange.
Katara would likely be shocked and initially angry. She has feelings for Aang and would be hurt by this unexpected turn of events. Zuko, on the other hand, might be conflicted. He wants his sister to be better but this situation is so out of the ordinary. Toph would probably be more straightforward and say what she thinks, which could be a mix of disbelief and amusement.
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.
Well, some Star Wars characters would probably view Earth military as primitive. In Star Wars, they have advanced energy shields and hyperdrive technology. However, they might also respect the Earth military's tenacity and the way they fight with honor. For example, Darth Vader might see similarities in the discipline of Earth soldiers to the Stormtroopers. He could also be intrigued by the concept of different branches in the military like the army, navy and air force as Star Wars doesn't really have such distinct branches in the same way.
Ruby would start to think about how the RWBY team could be more organized like the Earth military. She might see the value in having a more structured approach to fighting Grimm. Weiss would look at the Earth military's technology and wonder why Remnant hasn't developed similar things. This could lead her to question the reliance on Dust. Blake would be influenced by the way the Earth military works together. She might consider how the different faunus groups could cooperate better in Remnant. Yang would be amazed by the endurance and teamwork of the Earth military soldiers. This could make her more patient and less reliant on her own individual strength when fighting.