Once Nicholai heard May was Norman's daughter, Nicholai challenged May to a battle and sent Mudkip. Torchic launched Ember, which was negated by Mudkip's Water Gun. Due to May's inexperience, Torchic went to use Peck, but was defeated by Mudkip's Water Gun. Later on, Nicholai had Mudkip use Water Gun to knock off a fruit from a tree, to let Zigzagoon eat them. He also found one to battle and had Mudkip use Water Gun, which managed to knock Zigzagoon down, allowing Nicholai to capture it. Team Rocket captured Mudkip, but Nicholai managed to transform himself into different Pokémon and retake Mudkip before Team Rocket were defeated by Ash's Taillow.
After encountering the heroes once more, Nicholai sent Marshtomp, who evolved from Mudkip. Ash sent Treecko, who evaded Marshtomp's Water Gun. Treecko tried to use Quick Attack, but was stopped by Water Gun. Marshtomp managed to inflict damage with Mud Shot and tried to use Iron Tail, though Treecko retaliated with Bullet Seed. Using Pound, Treecko defeated Marshtomp and won the battle.