Sukuna is based on the same-named figure from Japanese mythology: Ryomen-Sukuna (両りょう面めん宿すく儺な?). He is a demonic/specter-like figure described in the Nihon Shoki (日に本ほん書しょ紀き Nihon Shoki?), said to have appeared in the Hida Province (today's Gifu Prefecture (...