Nack Tierce had dark brown hair, which was styled back in a somewhat spiky pattern. He had medium brown eyes and was somewhat tall when compared to the average of the other cadets from his squad. He wore the typical uniform of a member of the 104th Cadet Corps with a gray shirt underneath.
Nack appeared to be a warm-hearted person who cared a lot about his friends, which he did not seem to have much trouble making.
Nack graduates training as a member of the 104th Cadet Corps. After the second attack by the Colossal Titan, he is assigned to the middle guard including Eren Jaeger and Armin Arlelt in the Trost District. Shortly after the squad's deployment, the group is attacked by an abnormal Titan, which results in the death of Thomas Wagner.
This causes Eren to attack the Titan in a rage, but his carelessness causes him to get his leg bitten off by a Bigmouth Titan. This causes his squad to pursue and try to help him, but results in their deaths when a Titan swats Nack midair, Bigmouth Titan eats Milieus Zeremski and Mina Carolina who is hit when a Peering Titan grabs her wire and then eats her.
Armin would later report his demise to the remaining members of the 104th Cadet Corps, saying he died valiantly in the line of duty.