Nataku (那吒), an androgynous clone of extreme psychic ability, was born of genetic material of Kazuki Tōjō (塔城 霞月 Tōjō Kazuki), the deceased granddaughter of the president of Tōjō Pharmaceuticals, and her father Masaki.
After Fūma is badly wounded by the spell Sorata casts as he dies, he absorbs Nataku's flesh into his own and is healed. In the manga, Nataku dies when Fūma realizes their greatest wish, to die by the hand of the one they love most (Fūma, who resembles Kazuki's father) while protecting the person most important to them (Karen, who resembles Kazuki's mother).
Nataku is sent to retrieve the Sacred Sword by Chairman Tōjō, who wishes to destroy the sword so that Nataku cannot become entangled in the matter of the Promised Day. In the process of stealing the Sacred Sword, Nataku mortally wounds Kyougo Monou, Fūma and Kotori's father, who was attempting to protect the Sacred Sword. Nataku later battles both Karen and Aoki, the former refusing to believe Nataku can possibly be unemotional and regarding Nataku as a "lost child". Nataku is haunted by the memories of their previous life as Kazuki, and they follow Fūma unquestionably as Fūma resembles the person Kazuki cared most for - her father.
In Tsubasa, Nataku is one of the fighters of the City Hall faction. Nataku is also one of the characters who underwent most significant changes: unlike in X, Nataku is a mentally developed adult and takes care of Kazuki, alternate version of X's Kazuki (who substitutes Seishirō's place). In the X Tarot set, Nataku represents The Moon.