Ampharos, as the chief of the Expedition Society, is primarily involved in investigating the recent events of Pokémon being turned into stone by an unknown power. For this reason, Ampharos visits Serene Village, but due to his poor sense of direction, he gets lost in the plaza, dropping his Connection Orb in the process.
The player and partner first see Ampharos here, where they pick up his Connection Orb with the intent of returning it to him later. After school, the player and partner search for Ampharos who had been seen heading to Poliwrath River. There, despite initially defeating the Poliwrath Brothers, the unsuspecting player is almost attacked by one of them until Ampharos arrives to intervene. Later, the three gather at the hill with the big tree, where Ampharos denies being involved with the Expedition Society. However, he hands the player and the partner their Junior Expedition Badges, Bags and Gadgets, as well as his Connection Orb. After the player and partner leave, Ampharos gets into contact with Dedenne, where he is first revealed to be the chief of the Expedition Society.
Ampharos is seen that next day lost around Serene Village plaza again, where he meets the player and partner once more. Here, he explains how to use the Connection Orb to them formally.
The player and partner next meet Ampharos at Lively Town, where they discover that Ampharos is actually its chief. Ampharos rescinds his rule banning children from joining and officially declares the player and partner members of the Society.
Later, Ampharos leads the Society on an expedition to Fire Island where Entei lives, to confirm his suspicions that Entei was the cause of the Pokémon turning into stone. Proving to be false, Ampharos and the Society begin to suspect Krookodile, a local gangster. Ampharos decides to split the group into two, with Mawile, Buizel, Dedenne, and Bunnelby heading to the Prehistoric Ruins, while the player, partner and Archen head to Serene Village following Krookodile. However both teams become petrified, leaving only Ampharos and Jirachi left in the Expedition Society. Ampharos, along with Jirachi and Espurr from Serene Village, then start to make plans in defeating the evil power.
After the player and the partner escape the Voidlands, Ampharos, along with Jirachi and Celebi, are able to save them from a trap designed by Nuzleaf at the Prehistoric Ruins. Celebi, a close friend of Ampharos, teleports them away to safety, close to the Tree of Life. At the Tree of Life, it is revealed that Ampharos and Jirachi had rallied together many allies, including several Legendary Pokémon to stop Dark Matter. Ampharos then bids the player and the partner his wishes as they prepare for the final battle against Dark Matter.
In the epilogue, Ampharos arranges a plan with Mawile and Xatu to restore the player’s partner who had disappeared into the sky as a ball of light after defeating Dark Matter.
Spoilers end here.
Personality and characteristics
Ampharos is the leader of the Expedition Society who has a poor sense of direction. Despite this, he is trusted by the members of the Expedition Society. He is also rather forgetful, and tends to treat rules, even ones made by himself, as more of a suggestion than anything, and will occasionally either bypass or simply remove a rule that he himself may have made. Despite this, he is rather genuinely caring, and has the utmost confidence in all the societies members.