Carlo was a young 瑪雷an boy of short stature and slim build. He had a rounded nose and short blond hair parted down the middle. He wore round-rimmed glasses at all times as well as a standard Marleyan military uniform.
As a member of the 車力巨人's Panzer Unit, Carlo and three other of his comrades fought against the Mid-East Allied Forces at Fort Slava. Over a month later, 皮克 reunites with her Panzer Unit while she and 波爾柯‧賈利亞德 are escorted away from the 雷貝里歐 internment zone festival by a mysterious bearded soldier. Suspecting treachery, Pieck warns her Panzer Unit secretly to follow them from a distance.
When Pieck and Galliard are captured by the soldier, Carlo and his comrades come to their rescue. Realizing they are under attack by the 進擊的巨人, Carlo and the others in the Panzer Unit quickly prepare the Cart Titan's artillery armor for battle.
Joining the fight alongside Galliard's 顎巨人 and 吉克·葉卡's 野獸巨人 against the invading 調查軍團, Carlo assists Pieck by gunning down approaching soldiers, carefully conserving his ammunition as Pieck orders. However, when the Beast Titan is suddenly brought down by the Survey Corps' 里維·阿卡曼, the Panzer Unit is caught off-guard by a wave of soldiers overhead. In the chaos, 莎夏·布勞斯 carefully snipes Carlo in the forehead from across the rooftop, distracting the others of the Panzer Unit shortly before the remaining three are annihilated in a barrage of 雷槍.