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The ultimate Poké Ball — developed by Silph Co., capable of capturing any Pokémon without fail, and used by Red to capture Mewtwo in Cerulean Cave.
The Master Ball is Silph Co.'s greatest invention and the arc's most important MacGuffin. It guarantees capture of any Pokémon, regardless of power level — which makes it the only way to reliably capture Mewtwo, a Pokémon whose psychic defenses would shatter any normal Poké Ball. Red obtained the Master Ball and used it to capture Mewtwo in Cerulean Cave, with Pika delivering the throw at a critical moment during the battle. The capture worked not just because of the Ball's technology, but because Mewtwo chose to accept it — recognizing Blaine's remorse and Red's courage. The fact that only one Master Ball exists gives the capture permanent weight. There are no second chances. If Red had missed or if Mewtwo had been unwilling, the most dangerous Pokémon in Kanto would still be free.
A purple Poké Ball with a distinctive 'M' mark on the upper half and pink circular accents. Slightly larger than a standard Poké Ball. There is only one — Silph Co. created a single prototype before Team Rocket seized their facilities.
Also known as: Master Ball, the Master Ball