Zephyr was led by Rutger Claussell, known as the Jaeger King, until he and Baldur Orlando of Red Constellation resolved to settle the question of whom was the strongest jaeger corp on the continent with a personal duel. After a battle lasting three days and nights, with neither combatant tiring, the duel concluded with the mutual death of both participants. Unlike the Red Constellation which was centred around the leadership of the Orlando bloodline, and therefore having potential successors to rally around, the loss of Zephyr's central figure and commander resulted in the corps seemingly disbanding.
Two of Zephyr's regimental commanders, Leonidas and Xeno, were hired by Duke Cayenne and served as mercenaries for the Noble Alliance he commanded during Erebonian Civil War in late S.1204. It is later revealed that the group continued to operate in secret following the demise of Rutger and were pursuing a mission to 'bring him back'. They succeeded in this in S.1205 after it is revealed they undertook a contract with the leader of the Black Workshop, Black Alberich as part of a scheme to find a suitable awakener for Zector, the Palatinate Knight. The corps had previously conducted business with the workshop, making use of experimental 'S' weaponry such as Rutger's glaive, Xeno's blade rifle and Leonidas's armoured arm.
In the time-frame approaching the Great Twilight, Zephyr would continue to work for the gnomes, leading them into conflict with other underworld organisations such as Ouroboros. They worked alongside another jaegar corp Nidhoggr, joining forces when moving to confront the society at Juno Naval Fortress. Following the advent of the great twilight and the declaration of Operation Jormungandr's D-Day, Zephyr's business with the gnomes was concluded and the corps was free to prepare for the Rivalries.
Following the defeat of Rutger, the corps was left in the hands of Leonidas and Xeno who resolved to carry on and rebuild.
They would later assist in the assault on Reverse Babel alongside some of Ouroboros's forces, joined by former comrade Garcia.
- Rutger Claussell, The Jaegar King (猟兵王) (Deceased)
- Fie Claussell, Sylphid (西風の妖精 )(formerly)
- Garcia Rossi, The Killing Bear (キリングベア) (former)
- Leonidas, The Behemoth (破壊獣)
- Xeno, The Trap Master (罠使い)