Nicolo is a young Marleyan man of short stature and slim build. He has a petite pointed nose and is blond, with his hair falling to the sides, looking like he has an undercut. He was wearing the standard Marleyan military uniform when he was first captured by the Paradis military's Scout Regiment.
While visiting the cemetery, Nicolo wears a black suit and tie.
Nicolo was at first a very typical Marleyan, fearing the Eldians of Paradis Island and calling them devils. He was very disgusted with having been captured by them and having to live by their side, but after spending a lot of time with the Scout Regiment, he and his comrades have developed grudging respect and shaky friendships with the ones they once thought of as devils.
Nicolo seems to be somewhat courageous, disregarding his own life to beg his fellow soldiers to kill the islanders despite being held at gun point by them.
As a member of the first survey fleet's advanced party, Nicolo arrives at Paradis Island ahead of the main Marleyan vessel in 851. Sometime after being captured, the Attack Titan seizes the main vessel. Hange Zoë and Levi Ackermann threaten Nicolo with a blade in an attempt to make the navy soldiers comply. Despite being in danger, he screams for his naval captain to shoot the islanders.
In 854, hearing about Sasha's death after the battle of Liberio, Nicolo attempts to visit her grave to pay his respects, but is harassed by a member of the Military Police because of his Marleyan status. Jean Kirschtein and Conny Springer come to his defense, and Nicolo explains to them why he has come to the cemetery. Arriving at the grave, Nicolo asks to know how she died. Jean apologizes to him, blaming his own carelessness for Sasha's death, but Nicolo is confused as to why Jean is apologizing to him, pointing out that he was only their cook. He asks Conny how he is coping, but their conversation is interrupted by the arrival of Artur Braus and his family. After they have paid their respects, Nicolo introduces himself and offers to cook for them someday.