POKÉMON: THE MASTERMIND OF MIRAGE POKÉMON

Dr. Yung, an enigmatic Pokémon scientist, has developed a new Mirage system that uses computer data to resurrect extinct Pokémon, like Kabutops and Armaldo. Professor Oak, Ash and his companions show up at the Mirage Mansion at Dr. Yung's invitation, and watch a demonstration of the machine's capabilities. In the middle of a battle between Dr. Yung's Mirage Pokémon and Ash, the machine goes haywire and a Mirage Aerodactyl swoops in and kidnaps Dr. Yung. A man calling himself "The Mirage Master" appears and announces to everyone that the Mirage System can be used to create Pokémon with absolutely no weaknesses. Ash, Misty, and Professor Oak struggle to stop the madman and escape with their lives. (Source: Anime News Network) — Description from AniList community (anilist.co).