To develop Kai's character, start with his backstory. Decide where he comes from, his family situation, and any major events in his past that shaped him. For instance, if he grew up in a poor family, he might be more resourceful and determined to make a better life for himself. His appearance can also reflect his character. If he has long, unkempt hair, it could show that he's a bit of a free spirit.
Another storyline could involve Kai's relationships. He could fall in love with an OC from a different tribe. This would create a lot of drama as their tribes might have some sort of feud or different values. They would have to fight against the odds to be together, and Kai might have to prove himself to her tribe to gain their acceptance.
Well, without having read it directly, it could be a story that centers around the last avatar's journey. It could involve themes like self - discovery. For example, the avatar might be on a quest to understand their true identity and purpose. They could also be involved in a battle between good and evil, with their unique abilities being crucial in the outcome.
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.