Upon arrival, the prison's warden, Mui, applies the Katon: Tenrō (Fire Style: Celestial Prison) seal to Naruto. This seal drains his chakra whenever he tries to use it and subjects him to immense pain if he leaves the prison's range, effectively neutralizing his Nine-Tails power.
The Walls of the Blood Prison: An Analysis of Naruto Shippuden Movie 5: Blood Prison Upon arrival, the prison's warden, Mui, applies the