From Bulbapedia, the community-driven Pokémon encyclopedia.
An example of Kawahara's artwork
Wataru Kawahara is an illustrator for the Pokémon Trading Card Game. His illustrations premiered in the Beat of the Frontier expansion and its deck kit. The cards he illustrated include Cyrus's main Pokémon in the deck kit, Charizard G LV.X, as well as a couple Trainer cards in the main expansion. So far, he has illustrated 36 cards for the trading card game, and is expected to do more. For a list of cards he illustrated, go here.
He has also been credited for working on games such as Tales of Symphonia and Sonic and The Secret Rings.
Wataru Kawahara's Facebook