The world of “Pokémon” is evolving with “Pokémon Horizons: The Series,” a show with two brand new protagonists after Ash Ketchum finally caught ’em all and became the very best, like no one ever was.

As Ash set out on the first part of his journey, he built up his team to include Pokémon caught throughout the region of Kanto. Although Ash had been late to the party to receive the typical starter ...