This chapter opens with a description of the thunder spirit that inhabits the tower. It's called the "guardian of the tower" because it can transform a cannonball into a "high level thunder spirit" . The thunder spirit is said to be the last person to run for 200 years, and even practitioners of his school have been taught to run into him if they ever encounter a "ruined" person. The cannonball is transformed into a lightning bolt, which can travel at lightning speed. It also showers an area with "unlimited wind and thunder" , which makes the cannonball "like an exploding twice". The thunder-spirit is rumored to have been created by the "grandfa ther" and his grandfather, who were both "just as powerful" as the thunder-devil. The narrator tells us that the more he hears about this, the more "immeasurable" it gets . But legend has it that the grandfa's grandfather was just as strong as the lightning-devil, and that if the two of them can't defeat the thunder god, they won't have a chance against it . So the narrator tells the audience that if they can beat the thunder demon, they'll be "on the same level of fate" as they were when they were young. He also tells them that they're going to have to follow the plan, which is to "side stick" the lightning rod. The lightning rod is a special type of lightning rod that can only be used when the lightning bolt is in its lightning form , so it's impossible for thunder-demon to attack it with magic. But the narrator says that