Pokémon 3 the Movie: Spell of the Unown (2000)

Ash and his friends arrive in the city of Greenfield for a Pokémon tournament! They meet a girl named Molly Hale, whose father, a Pokémon researcher, has disappeared. Her deep passion for her missing father manifests in the Legendary Pokémon Entei, who starts to create an illusory world known as the Unown dimension! By exploring themes of love, family, and the power of imagination: You have to say “I Chose You!”.