Superman's speed in comics varies depending on the storyline and the writer. Generally, he can fly at supersonic speeds and even approach the speed of light in some cases. His speed is often used to save the day and overcome impossible odds.
Since I haven't read the story, I can't say for sure. But it could be the person whose words are described as flying, perhaps someone like a young person trying to prove themselves with their speech or writing.
I'm not sure specifically as I haven't read this story in detail. But generally, it might be about someone expressing themselves very quickly or perhaps the power of words to achieve something at a rapid pace.
Maybe he uses some new jutsu. For example, he could have developed a special chakra - based technique that allows him to manipulate the air currents around him, much like how some wind - style jutsu work. This would give him the lift he needs to fly.