Professor Samuel Oak is a central figure in "Pokémon: The Mastermind of Mirage Pokémon." He accepts Dr. Yung's invitation to witness a new battle system at Mirage Mansion, joining Ash, Misty, May, Max, and Brock. Oak recognizes Dr. Yung's research and identifies the technology as a "Mirage Field" during a holographic Pokémon demonstration.

When the system malfunctions, a masked Mirage Master seizes control. Oak is captured by a Mirage Aerodactyl and held hostage with Dr. Yung. The Mirage Master demands Oak’s global research database password to create a Pokémon without weaknesses. Oak refuses until the villain subjects Pikachu to agonizing memory extraction. To halt Pikachu’s suffering, Oak surrenders the password "REDGREEN."

The Mirage Master accesses worldwide databases, including Pokémon Centers and Professors Elm and Birch’s labs, creating an invincible Mirage Mewtwo. Oak deploys his Dragonite against it. Dragonite unleashes Twister, Hyper Beam, and Dragon Rage but falls to the Mirage Mewtwo’s overwhelming power.

After the Mirage Master unmasks as Dr. Yung—seeking revenge for discredited work—Oak deduces his identity. Oak witnesses Mew sacrifice itself to shield Pikachu from an attack and the Mirage System destabilize when Mewtwo resists Dr. Yung’s control. Following the system’s destruction and Dr. Yung’s disappearance into the wreckage, Oak reflects that "even data has a soul."