Well, without having read it specifically, I can only guess. But generally in the Airbender world, it's a place full of elemental powers. So this novel might tell the story of the last airbender's struggle. It could be about their fight against the forces that are disrupting the balance in the world. They might be on a quest to find other airbenders who might still be alive, or to master all the airbending skills to become a true savior of their world.
I'm not entirely sure as I haven't read it in detail. But generally, it might be about the water - bending aspects in the Avatar universe, like the water benders' skills, their culture, and perhaps their role in the story of the last airbender.
It depends on what you're looking for. If you're a huge fan of the 'Avatar: The Last Airbender' series, then it's probably worth it. The novel can give you more details about the characters and their adventures. However, if you're not that into the series, you might not find it as interesting.
Since it's about the last airbender, that character would be central. There could be a mentor figure, perhaps an old airbending master who left some teachings for the last airbender. And also, there might be antagonists, like powerful fire benders or some dark force that wants to stop the airbender from achieving their goals. And don't forget about possible friends from the earth and water tribes who join the airbender on their journey.
It's about the world of Avatar. It likely follows the adventures of the last airbender, with his journey to master different elements, face enemies, and restore balance to the world. There are probably epic battles, unique characters, and a richly detailed fantasy world within its pages.