In the world of Pennon and Battle, each faction has a unique understanding of the use of source power. The Sacred Oath Alliance of humans and dwarves perfectly integrates machinery with source power spells. The dwarves, with their advanced mechanical craftsmanship, completed the steam revolution early and entered the mechanized era; humans relied on agriculture and commerce for stable development, establishing a united and prosperous nation.
However, the sky remained the domain of birds and dragons. The Sacred Oath Alliance's troops, relying solely on dwarven drills and cannons, were insufficient to deal with aerial threats. At that time, dwarven flying machines were limited by the insufficient power of steam engines, requiring them to reduce size and carry no weapons to lighten the load, which was not suitable for large-scale military operations.
Thus, a wind spell master from the human battle mage corps, after long research and experimentation, successfully used wind spells to improve steam machinery, helping the Alliance's dwarven engineers solve the power issue and further promoting the birth of large flying vehicles, the Air Fortress. This wind spell master is now the spell advisor of the Sacred Oath Alliance—Sandar.