Born on Abstalia in the early months of the Great Liberation, Eihwaz was raised and trained for war in service to Rin Sakaros, like all Massassi. In 116 ABY, he relocated along with the rest of his species to Kavez Massass.
In service to the Royal Army, Eihwaz was assigned to several different Massassi Cohorts, distinguishing himself enough that at some point he earned a spot in the elite 11th Massassi Cohort. He was given an officer's commission and by 149 ABY was the colonel in charge of the entire Cohort.
Colonel Eihwaz acted as second-in-command to Legate Aria Nikina at the Defense of Daispin, and conducted most of the actual command himself, leaving Aria free to fight on the front lines and duel Sacco Vyrak. Eihwaz also assisted in Breek Zagrev's assault on Ador Hentral's flagship during the Battle of Dolomir. Nikina recommended him for the Sovereign's Order, and he received the decoration shortly after the war.