Zast, holding the rank of Lieutenant, was a Chev of male gender, born free, who fought for the Alliance to Restore the Republic throughout the Galactic Civil War. As a member of the Alliance Special Forces, he found himself a part of the Nishr Taskforce in 0 ABY. Functioning as an aide to the commanding officer, Major Fisk Csino, Zast also contributed to mission planning and the coordination of base operations at the company's headquarters, known as Nishr Base Seven.