Lord of All: I'm the Only One Who Didn't Get a Random Unit?

Billions of people came to the Endless Continent to become city lords and participate in the struggle for hegemony among all races! At the beginning of the arrival, each city lord can randomly obtain an initial unit building. However, Ye Xuan was shocked to find that he was the only one who was not randomly assigned to any troop type! ! Ah, here, there are no arms, wouldn't it mean that he died where he was? ! Fortunately, there is a system bug! The main city has become a unit of troops and a mobile castle. Not only can it be moved around to plunder resources, but all buildings in the city can be upgraded infinitely without restrictions! ! Ordinary main cities can be infinitely upgraded to god-level main cities, and ordinary defense towers can be upgraded to god-level defense towers... "My Black Dragon Legion, the top unit, can't even break through the city wall?" "Break the city wall? Once you have seen the terrifying scene of tens of thousands of god-level defense towers firing, I guarantee you that you won't even dare to get close to the city wall..." "No! The main city is coming again, silly kids, run away!!" This book is also called: Shock! My unit is the main city, a mobile tower defense game, and everything is true within the range. This novel and its characters are purely fictitious. Any similarity is purely coincidental and should not be imitated.