Idle Transfiguration (無む為い転てん変ぺん Mui Tenpen?) is Mahito's innate technique. It grants him the ability to distort the shape of souls and transfigure their respective bodies as a result. Idle Transfiguration allows the user to reshape the soul of themselves or anyone they physically touch. The shape of the body is dependent on the shape of the soul, so if the soul is distorted, so too is the body. Therefore, someone using Idle Transfiguration can disfigure their target's body into something grotesque by warping their soul's shape with just a touch. This process creates what are known as "Transfigured Humans" (改造人間 Kaizō Ningen?). This cursed technique attacks the soul directly. Only under certain circumstances can someone protect their own soul and anyone who cannot is instantly killed or deformed by Idle Transfiguration. All ordinary people eventually die after having their soul transfigured. The user can also reform the shape of their own soul and heal any injuries their body sustained in battle. This renders traditional means of injuring the user useless, as their soul must be attacked to do any significant damage. The user can even transform their body to give them an advantage, such as giving themselves wings for flight or shrinking their body to avoid an attack. An individual facing the threat of Idle Transfiguration can stay out of range and use cursed energy to protect their soul from being distorted. Techniques like Nobara Kugisaki's are especially difficult to handle as her ability is not only long range but can attack the soul directly through sympathetic resonance. Mahito called her a "natural enemy" of his due to this. However, Idle Transfiguration can still injure the body if the user touches their target, even if it doesn't fully distort their soul enough to deal a fatal blow. Even so, after two or three more direct to attacks to the soul, even if it's being protected by cursed energy, the target will no longer be human.
