Levi is known as humanity's most powerful soldier. He's ranked as Captain of the Scouting Legion division. Levi is also the leader of the Special Operations Squad, an elite team that he hand-picked in order to protect Eren Yeager. While it is said that he is blunt and unapproachable, it is noted that he has a strong respect for structure and discipline. There are rumors that he was originally part of underground crime before he became a soldier. Although he often appears to be unfriendly, he cares deeply for his team and has never undervalued human life. He is also a notorious clean-freak.

A stark contrast to his best friend Gon, Killua is highly mature in both thinking and emotion. He can keep his anger in check and maintain rationality better than Gon even when facing a terrifying experience.