As a Lairon, it was used to battle Brandon's Regice, despite Lairon having the major type advantage as both rock and steel-types are strong against ice-types, it was only able to use Iron Defense before being frozen by Ice Beam and finished off with Zap Cannon.
During Paul's battle with Ash in the Lily of the Valley Conference, it was revealed that Lairon had evolved. Aggron battled against Ash's Pikachu. Pikachu counters Metal Claw with Iron Tail, and stops Metal Sound with Thunderbolt. After Pikachu's signature Volt Tackle was blocked by Flash Cannon, Pikachu was switched out and replaced by Infernape. Aggron used Double-Edge while Infernape countered with Flare Blitz. Due to its Rock Head ability, Aggron was immune to Double-Edge's recoil effect. However Infernape's Flare Blitz was strong enough to burn Aggron and when Aggron attempted to use Flash Cannon, Infernape hit it with Mach Punch before it could launch the attack, knocking it unconscious. While he gave it his all while using Aggron, the defeat helped Paul to uncover Ash's strategy, which helped Drapion defeat 3 of Ash's Pokémon in a row.
- Kenta Miyake (Japanese and English)