Metal bears a strong resemblance to his father: he has shiny black hair worn in a bowl-cut style, dark eyes, and very thick eyebrows. His eyes, however, are noticeably sharper. His likeness is further perpetuated by his attire: he wears a green jumpsuit with orange leg and neck warmers and bandages over his hands. In Boruto, he exchanges his neck warmer for a scarf.
Metal is a hot-blooded and dedicated shinobi, much like his father Rock Lee, who he has sincere respect for, and his father's sensei Might Guy. This was exemplified when he was seen participating in his father's gruesome training regime.
Lee seems to suffer from social-anxiety, always worrying about people's views of him and wanting to impress others. He also seems to have stage-fright, as when too many people watch him, he locks up and becomes unable to move or fight properly.
Like his father, Lee specialises in taijutsu, and while not overwhelmed by his insecurities, is recognised as a genius within his taijutsu-excelling clan. Even while only in the Academy, he's shown great stamina and endurance, keeping up with his father's training. Lee shows impressive shurikenjutsu-prowess, able to effectively aim for targets even from behind and likewise hit the target with two shuriken simultaneously. His strength is noticeably high for his age, able pummel rocks with his strikes and likewise accidently break a videogame system between his hands. Also, while being influenced by mysterious dark chakra, he's demonstrated he can open at least three of the Eight Gates. As a genin, he was capable of holding his own against Shinki, as well as repelling his puppet into a wall with a single kick. He shows noticeable reflexes and dexterity, able to seamlessly catch multiple shuriken between his fingers.