It was said that it was very simple to make explosives before the catastrophe. In that age, people had grasped a lot of methods to explode substances. They could also make bombs with terrifying power. With only one bomb, they could even destroy a city, killing millions of people. Many people could even easily make a lot of explosives at home.
With the arrival of the catastrophe and the God's star, every rule in the world had changed, which caused people to lose their ability to make explosives for hundreds years after the catastrophe. This lasted until the time before the second holy war between humans and demons, when during an excavation of underground relics and under the enlightenment of far-east civilization, people gained this ability once again. It was said that this ability was related to crystals. However, compared to before the catastrophe, the number of people who were able to make explosives was even less than the number of rare animals in the zoo before the catastrophe.
[1] In ancient China, a king told a chancellor to present an elephant to a group of blind people. The blind people then touched the elephant with their hands. One touched its ear and said it was a winnowing fan; one touched its head and said it was a rock; one touched its nose and said it was a round wooden bar, bigger on one end and smaller on the other end, which was used to grind rice in ancient China; one touched its foot and said it was a mortar; one touched its back and said it was a bed; one touched its abdomen and said it was a jar; one touched its tail and said it was a rope.