Kazuma is a key character. He's a normal guy from our world who has to adapt to the crazy Konosuba world. Aqua is the goddess who brought Kazuma there but is often more of a hindrance. Megumin is known for her love of using explosion magic which has its own set of consequences. Darkness is the crusader who has some rather unusual, masochistic tendencies. These four characters are at the center of the story in 'konosuba last light novel'.
We can expect an exciting conclusion to the Konosuba story. It might have more of the hilarious misadventures of Kazuma and his party. There could be new challenges for them to overcome, and perhaps some unexpected character developments. Maybe we'll see more of the unique magic and skills in the Konosuba world.
Yes. If you're a fan of the series, it's definitely worth reading. It's the conclusion of the story you've been following, so it's like getting the final piece of a puzzle.
The Konosuba light novel is not a fanfic. It has its own unique plot, characters, and world-building developed by the author's imagination and creativity.