Item from pokemon-adventures-yellow by
Blaine's containment device for Mewtwo — not just a capture tool but a medical necessity, limiting the psychic strain that would otherwise kill them both.
The Master Ball containing Mewtwo is more than a capture device — it's a life-support system for both Blaine and Mewtwo. Mewtwo can only remain outside the ball for three minutes before the psychic strain on both of them becomes dangerous. The ball regulates the connection between Blaine's cells and Mewtwo's, keeping the bond from overwhelming them. During the battle against Lance, the Master Ball's three-minute limit creates tactical urgency. Every second Mewtwo fights is a second closer to Blaine's collapse. When Blaine does collapse, Mewtwo forces itself back into the Master Ball — choosing the prison over watching its creator die.
A purple and white Poké Ball with an M insignia on top. It hums faintly with psychic resonance when Mewtwo is inside — a prison that's also life support.
Also known as: Master Ball, Blaine's Master Ball