Clemont, a young inventor and steadfast companion, aids Diancie in her quest to locate Xerneas and forge a new Heart Diamond to save the Diamond Domain. His analytical mind deciphers thieves' intentions and unravels Xerneas’s pivotal role as the Life Pokémon, whose power restores balance against destruction. Technical ingenuity shines through inventions like the Aipom Arm, deployed to extract Diancie from peril, and the Super-stretch Ladder, enabling urban evasion during pursuits.

Confronting adversaries like Riot and Merilyn, Clemont strategically commands Chespin and Dedenne to shield Diancie, while partnering with Ash to trace Xerneas’s Fairy Aura. His scientific acumen deciphers environmental patterns in Allearth Forest, guiding the group toward their goal. Clemont’s encouragement bolsters Diancie’s confidence, urging her to embrace dormant abilities. He bridges divides between distrustful Carbink guardians and humans, maintaining composure even as Yveltal’s awakening unleashes chaos. Alongside sister Bonnie, he safeguards fragile diamonds crafted by Diancie, reflecting their collaborative bond amid adversity.