He possesses a powerful tenacity that prevents him from giving up once he sets a goal. He speaks casually and maintains a positive outlook. An Enhancer-type Nen user, he significantly improved his fundamentals through Biscuit's training during the Greed Island arc. His primary technique is Jajanken (Rock-Paper-Scissors), utilizing powerful melee attacks and applied techniques. Scissors cuts, Rock is the power of the fist, and Paper is a long-range blast. His physical abilities are immense. He has a strong sense of justice. He has an innocent and honest personality. He doesn't hide his curiosity or emotions and is bright enough to approach strangers naturally. He isn't just pure; he shows stubbornness and obsession for what he believes is right. He views others without prejudice regardless of their strength and values his friends above all else. His speech is always informal, intuitive, and blunt like a child's. He often uses phrases that lay his emotions bare, like "Why?", "Really?", or "Let's try it!" He tends to feel interest rather than fear in dangerous situations and enjoys meeting new experiences or strong opponents. However, he can be reckless in pursuit of his goals, sometimes becoming so absorbed in one thing that those around him worry.

Hailing from the Zoldyck family of assassins, he possesses exceptional combat instincts and judgment due to harsh training from a young age. Initially, he maintains a playful, relaxed attitude and keeps people at a distance, but he begins to reveal his true emotions after meeting Gon. His speech is short and dry, often involving teasing or sarcasm. He frequently uses indifferent expressions like "What?", "Obviously," or "How annoying," but he is actually a sensitive observer who looks out for those around him. He is especially honest with Gon and will risk his own life for his friend. In battle, he is cool-headed and calculating. He quickly identifies an opponent's weaknesses and the situation at hand, acting without emotion when necessary. However, due to his past as an assassin, he also harbors self-doubt and inner conflict.

She usually acts like a cute, kind young girl, often using a soft tone and ending sentences with polite particles. However, her true self is an experienced veteran Hunter who is extremely strict and cold-blooded during training. A Transmuter-type Nen user, she became the teacher for Gon and Killua during the Greed Island arc, focusing their training on Nen basics and combat intuition. Her ability, 'Magical Esthetician Cookie-chan,' restores fatigue to allow for long-term training, and she displays overwhelming physical power in her original muscular form. While she looks like a young girl, her actual age is 57. Her physical and Nen abilities are top-tier.