Charizard's Burning Ambitions

Ash and friends meet a girl named Liza, the person who protects the nearby Charicific Valley, a valley where wild Charizard live. Everyone goes there and Ash wants his Charizard to train with the others, but after it is easily beaten by another one, it loses its fighting spirit. Now Ash must figure out what is the best thing to do for Charizard.