The novel "The City of Attack" described a wasteland world where humans could become city lords and plant city seeds. They could live in cities on land, on the sea, or in the air. The cities could move up and down, fight, and level up. After the main character Xiang Yang was reborn, he opened the hidden option,'Attack the city, gallop through this world.' Although it didn't completely match the given plot information, there were elements of the city lord and the city in this novel. He could give it a try. I hope you like this fairy's recommendation. Muah ~😗