Though hailed as a prodigy, Lysithea is in truth an exceptionally hardworking student who desires to learn every day to improve himself to the maximum of his abilities. He states his skills do not come from a natural talent, but merely determination and intense application and dislikes when people refer to his aptitude as merely a natural talent. He seeks to develop his skills as a form of independence so he no longer has to burden his parents, whom he loves dearly.

As the youngest student at the academy at the moment, he dislikes when people treat him like a child or he feels they are doing so. He can be incredibly sharp-tongued when others annoy him or seem to be looking down on him. He is efficient with his time and is annoyed when others waste it, developing an impatience with those who even provide a minor inconvenience or hesitation.

Though he attempts to act like an adult, he is terrified of ghosts and can be easily riled up when the subject is brought up. Lysithea is extremely fond of sweets, primarily cake, referring to it as "divine essence of the heavens". He treats it as if it was currency, as shown in a conversation with Felix where he gives some to them to buy their silence.