Clemont is the fifth Gym Leader to be faced by the player. At some early point in the game, he gives a device that solves electronic puzzles to Shauna. He first appears outside the Prism Tower with his little sister, Bonnie, lighting it up. He will give TM24 (Thunderbolt) after being defeated. According to the television show Gym Freaks, he is currently developing a machine that enables him to run faster, which is apparently his worst talent. It also states that he has secretly started to save money to go to the amusement park in the Unova region. He is described as a genius, having been credited with the invention of Super Training. Despite this, many of his inventions apparently fail to work.
April: "Hello! It's time for Gym Freaks, your source for the hottest news about hot Gym Leaders in Kalos. So... I'm now in front of the Lumiose City Gym! ... Eeek! Clemont has arrived! He's cute! So cute! His glasses make my heart twinge! Clemont has secretly started to save money to go to the amusement park in the Unova region. Awww... I want to donate money to his park fund! Oh... He went inside the Gym... That's all for the on-site report. Good-bye for now, everyone."
April: "Hello! It's time for Gym Freaks, your source for the hottest news about hot Gym Leaders in Kalos. So... I'm now in front of the Lumiose City Gym! ... Yeek! Clemont has arrived! He's cute! So cute! His glasses make my heart flutter! Clemont is also known as a genius inventor. But even such a genius has something he's not good at. That is...running. Lately, he's been developing a machine that enables him to run faster. Oh... He went inside the Gym... That's all for the on-site report. Good-bye for now, everyone."
Clemont debuted in Charging After Electrike. He was first seen in Cyllage City alongside Grant, who was helping him find Electric-type Pokémon to power the Prism Tower during a blackout. After witnessing Grace, a famous Rhyhorn racer, being found and taken away by several Team Flare Grunts, the two were left wondering what happened. In Fast-Thinking Froakie, Clemont found Grace's daughter, Y, and her friends chasing an Electrike on Route 5. After Electrike was defeated, it evolved into a Manectric and revealed it wanted Y to retrieve a Manectite stuck in a tree. Overhearing the commotion, Clemont introduced himself and offered to help get the Mega Stone in Y's place. Before Clemont could grab the stone, a Team Flare Grunt stole it and fled, causing a tree to fall on top of Clemont. X and Trevor went after the Grunt while Y helped free Clemont, who revealed what he saw happened to Grace in Cyllage.
In Morphing Manectric, Clemont and the others were saved by Cassius, who defeated the Grunt's four Espurr. With the Espurr held captive, a curious Clemont took checked to see what was under their ears, causing him to be sent flying by the Espurr's unrestrained psychic power. The Grunt that stole the Manectite later found Clemont's unconscious body and captured him. In Shooting Frogadier, Clemont awakened in the Team Flare Secret HQ, where he was greeted by Xerosic, one of Team Flare's scientists. Xerosic freed Clemont from his bindings and ordered him to build a machine for Team Flare. Clemont initially refused, but was forced to comply after seeing Xerosic use his Heliolisk as a hostage.
In Quilladin Stands, the device was finished and given to Lysandre. With Clemont having served his purpose, Xerosic order some Grunts to throw the boy down an incinerator chute. Using his Aipom Arm's camera function, Clemont discovered the Secret HQ was located in Geosenge Town. Around the same time in Laverre City, X received a pair of glasses belonging to Clemont from a wild Klefki. Using the glasses, he also discovered where the Secret HQ was hidden and set out to confront Team Flare.
In Flabébé Blooms, Trevor, Tierno, and Shauna made it inside the Secret HQ, where they reunited with Clemont and freed AZ, a giant man that was held prisoner. Clemont helped launch Trevor and the others to where the ultimate weapon's key was held, but they were unable to pull it out in time before it fired. To Lysandre's frustration, the combined efforts of X, his friends, and the Gym Leaders successfully weakened the ultimate weapon, preventing it from taking any innocent lives. AZ stayed behind to allow Xerneas to take Clemont and the others back to the surface. Once Xerneas joined Y, they attempted to destroy the ultimate weapon, but were interrupted by Malva and her Yveltal. Due to Xerneas and Yveltal being evenly matched, Xerosic announced that Lysandre ordered a ceasefire. Xerxer confirmed this and retreated, taking everyone with it.
In Pinsir Glares, Ramos revealed that Team Flare blamed the destruction caused by the ultimate weapon on the Gym Leaders and the Vaniville children. X and his friends were advised to keep out of the public's eye while the Gym Leaders helped rebuild the damaged areas. In Zygarde Agitated, Clemont, Bonnie, Alexa, Viola, and Yvette confronted Team Flare at Route 10. Together, the group managed to successfully free the Pokémon Team Flare had captured. After Team Flare was fully defeated, Clemont and his allies met with X and his friends at Lumiose City to congratulate them on their victory. He and Bonnie returned Furry, Shauna's missing Furfrou, to its Trainer. Clemont also gave Trevor Malva's Delphox, who they faced on Route 10, due to Furry recognizing it as an ally.
Heliolisk is Clemont’s only known Pokémon on hand. It was used by Xerosic as a hostage to force him to build a machine for Team Flare in the Team Flare Secret HQ. It was later seen with him and the others on Route 10, freeing the Pokémon that Team Flare had captured.
This Furfrou originally belonged to Shauna. It was caught in an explosion at Vaniville Town and was separated from its Trainer. Afterward, it found its way to the Pokémon Village, where it was captured by Team Flare in order for its life energy to be used as fuel for the ultimate weapon. It was rescued by Clemont and his friends and was later returned to Shauna.
This Delphox guarded the life energy extraction process on Route 10. She battled against Clemont and his allies in order to prevent them from stopping Team Flare from reactivating the ultimate weapon. Although she fought hard with powerful attacks, Delphox eventually fell during the battle. After the battle, Shauna's Furfrou guarded the unconscious Delphox, as it recognized her as the Fennekin that was with Trevor before being lost in an explosion. Realizing that she must be connected to X's group, Clemont took Delphox with him and gave her to Trevor.
Clemont Cards listed with a blue background are only legal to use in the current Expanded format. Cards listed with a green background are legal to use in both the current Standard and Expanded formats.