As long as there's enough gunpowder, pure enough, not just a bronze door, even a large mountain can be blown open.
Now Zhang Chen has money, so naturally he doesn't need to painstakingly extract materials for gunpowder himself. Zhang Chen directly transforms into a Vampire Bat and comes to the county town, then uses silver to purchase various materials in the city.
Zhang Chen bought many materials for explosives; fortunately, he had the help of the Fox Spirit, who tirelessly transported them back and forth.
After purchasing dozens of times, Zhang Chen returned to the cave and said to the Fox Spirit, "I'll personally demonstrate how to make high-explosive gunpowder. You have to learn well because you'll be responsible for making gunpowder in the future."
Fox Fairy Nannan widened her eyes and carefully watched Zhang Chen's teaching.
