Billions of Magic City: I'm the Only One Pursuing Technology

Hundreds of millions of people around the world collectively come to the world of high magic, and a random magic city starts. Billions of cities can cooperate with each other and compete with each other. Someone pointed out the dragon's nest, and the fire dragon burned, killed and plundered it. Someone established a mermaid dynasty in the sea, controlled the ocean, and built an invincible fleet. Some people live underground, develop alchemy secrets, and become rich through mining trade. There are even people who are so lucky that they possess the only black magic power and summon an army of millions of undead at the beginning. Xiu Ming just traveled through time and clicked on the only special cornerstone: the technology development tree! "Damn it, how come my max-level fire dragon was pierced by a steel needle eight hundred meters away?!" "What kind of boss is this? He actually ordered 10,000 tons of iron ore! What are you building, an electromagnetic rail gun...?!" "The Lunar God Clan will attack us next month!" The whole world was panicking, but Xiu Ming responded calmly: "The second heavily armored mecha army is ready to attack!" This novel and its characters are purely fictitious. Any similarity is purely coincidental and should not be imitated.