Flash Step, also known as 瞬歩 (Shunpo), is a high-speed movement technique used by the Shinigami (Soul Reapers) and other spiritual beings. It allows them to move at incredible speeds, effectively disappearing from one location and reappearing in another instantaneously. Flash Step is primarily used for combat purposes, allowing the user to swiftly dodge attacks, close the distance with opponents, or launch surprise attacks. It requires the user to focus their spiritual energy and use precise footwork to move quickly and smoothly.