Why Does Ash Not Use Charizard?

It was there that he renewed his vow to become a Pokémon Master and decided to leave most of his Pokémon — including Charizard — with Professor Oak. With the long relationship Ash and Charizard have had, this may have been surprising, but it made sense for Ash's character evolution.

Does Ash still use Charizard?

Charizard was reunited with all of Ash's Unova Pokémon at Professor Oak's Laboratory in The Dream Continues!. He joined the others in a group attack on Team Rocket with his Flamethrower to send them blasting off for the last time in Pokémon the Series: Black & White.

Why is Ash not using Charizard?

Ash Ketchum decided to leave his Charizard in the Charicific Valley because he thought it would be better for him to stay there and train. He did not actually release him as he did with some other Pokémon, he just allowed him to be with his own species.