In Mecha World, for every ten major cities, there would be a sky metropolis connecting these ten major cities. As its name suggests, the sky metropolises existed in the sky. However, these sky metropolises were not for human inhabitation; they merely functioned as spaceports.

Every day, there would be massive numbers of spacecrafts, military vessels, and cargo ships passing through these metropolises, departing from them or merely stopping by. Many lone wolves, expedition parties, and battle clans which needed to travel to distant lands for their missions would need to enter the sky metropolises to hitch a ride on a starship or some cargo ship. However, though battle clans could freely choose between military vessels and common ships, regular lone wolves and commoner expeditions could only ride civilian spacecrafts.

This was another reason why battle clans were so popular in Mecha World. After all, in Mecha World, 70% of ships were military vessels of the Federation. Furthermore, som