Pokémon Double Trouble - S2.E28

On Kumquat Island, Ash discovers Luana, the final Orange Island Gym Leader, who mistakes him for her son. After defending the island from Team Rocket, they head to the Gym to have a Double Battle where Pikachu and Charizard battle against Marowak and Alakazam but Pikachu's and Charizard's unwillingness to work together might end up costing Ash his chance of qualifying for the Orange League.