Dustin

John's Dustox (Jon's Dokucale) is the second Pokemon obtained by John. She was a mistreated Wurmple when John first met her, and he decided to challenge her former trainer, Greg, by using Wurmple against him to prove that it is not worthless. In this battle, Wurmple evolved twice into her final stage, but still lost the battle. Upon further training, Dustox was used to battle Greg once more, resulting in a massive win for her. Greg attempted to steal Dustin back, but John protected her and decided to keep her.

With Greg
Dustin was a mistreated Wurmple under the hands of her abusive owner, Greg, who only used powerhouses and released his weakling Pokemon. Dustin was one of his victims.

With John
Disgusted by Greg's manner of training, John captured Dustin and challenged Greg to a battle. Dustin evolved twice, into her final stage as a Dustox, but still lost the battle to Greg's powerful Mudkip. Greg called the two of them weak and left. Dustin has since grown into a mature, yet powerful, special attacker. She has an array of different attacks and is useful against many Pokemon, having been vital in many of his Sinnoh gym battles. After much training, John met up with Greg once more and challenged him to another battle. In this battle, Dustin left victorious, and Greg wanted Dustin back. He tried stealing her from John, although John protected her and told him that Dustin was her's. Greg remained adamant, but John used his Luxio to electrocute Greg and send him away. John and Dustin's bond continues to grow, and the two of them seem to share a good relationship.

In the league, Dustin proved powerful against Aaron, using Psychic and Sludge Bomb to its advantage against the other Bug-type Pokemon. Dustin was also used against Lucian, where it defeated his Mr. Mime, but fainted at the hands of Alakazam.

After the league battles, John decided to start off in a new region with a clean slate. So he left Dustin, alonside his other party Pokemon, at his home in Twinleaf Town before setting off with his baby Mijumaru, nicknamed Blue Moon, to the Isshu region with his friends.