Oliver serves as the mayor of Fula City, a role he inherited from his predecessor that binds him to a great secret. He is the guardian of a lie created fifty years prior, when a fire ravaged the mountain forest as humans searched for the Mythical Pokémon Zeraora. To protect the creature, the previous mayor spread the story that Zeraora had perished and cursed the mountain—a fabrication Oliver continues to uphold.

He is also a father to a young girl named Margo, whom he cautions with care when she leaves for the festival. Unbeknownst to Oliver, Margo has discovered Zeraora alive in the forest and has been secretly tending to it after it saved her and two other Pokémon from a rockslide.

When a crisis descends upon Fula City through a released Effect Spore and a spreading fire, Oliver joins the search for the missing eternal flame, a beacon used to summon the Legendary Pokémon Lugia. After the crisis is resolved by the combined efforts of the city’s people and Pokémon, Oliver makes a pivotal choice: he publicly renounces the long-standing deception of Zeraora’s death and declares a new era of peaceful coexistence between the citizens and the Pokémon. His leadership shifts from preserving a protective falsehood to championing openness and harmony.