C268 Paying Debts at the Door(3)

A Martial Lord's typical flying altitude is around 750 feet. For every additional half-mile ascended, the consumption of elemental energy doubles. This is precisely why the city walls stand at 300 feet—to sap the elemental energy of any attacking Martial Lords.

Xiao Yong followed the Martial King, ascending higher. The four Martial Kings were momentarily taken aback