A member of ZAFT's Creuset Team and the designated pilot of the Duel Gundam. He is a second-gen Coordinator with elite lineage, and a proud man who makes no effort to hide his disdain for Naturals. He has a strong sense of rivalry with his military academy classmate Athrun Zala. As a member of the Creuset Team, he took part in the attack on the neutral colony Heliopolis and succeeded in capturing the Earth Alliance Force's G Weapons. After that, Kira Yamato and his Strike Gundam caught Yzak off-guard and left him scarred across his face. He chose not to remove the scar and vowed revenge, becoming obsessed with hunting down Kira's mothership, the Archangel.