Grant appears in Pokémon X and Y as a Gym Leader. Trainers who defeat Grant will receive the Cliff Badge, along with TM39 (Rock Tomb). He excels at a variety of sports, such as bike racing and mountain climbing. According to the television show Gym Freaks, he is a trend setter and very fashionable, with his hairstyle of rolling stones apparently being popular with young people. It also states that he cuts down on his eating to keep his weight down, but appears to miss the opportunity to eat sweets because of this.
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 Cyllage City Gym! ... Whoa! Grant has arrived! He's good looking! So good looking! Lean yet muscular. Fascinating! That hairstyle of rolling stones into your hair is very popular among young people now! Grant is not only a Gym Leader but also a leader in fashion! 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 Cyllage City Gym! ... Whoa! Grant has arrived! He's good looking! So good looking! Lean yet muscular. Fascinating! But I know that he cuts down on his eating to keep his weight down! I saw him longingly looking at sweets in front of a café. He's so cute! Oh... He went inside the Gym... That's all for the on-site report. Good-bye for now, everyone."
In Climbing the Walls!, Grant accepted Ash's Gym challenge after the latter's arrival at the Cyllage Gym. Unlike most Gym Leaders, he allowed Ash to use his entire team against him while he would only be using two Pokémon. After some hard battles, Ash emerged victorious and Grant awarded him the Cliff Badge, telling Ash that he would like to battle him at the Battle Chateau sometime.
Grant cannot resist scaling walls, including the wall of the historic Battle Chateau, simply for the challenge that climbing offers. He has built the Cyllage Gym with his rock climbing hobby in mind, and readily challenges his opponents to scale the difficult rock walls up to the battlefield to test them. Grant believes that rock climbing offers a person, quite literally, a different perspective and access to a state of enlightenment. He draws on his clarity of mind for strength and concentration during his Gym battles. He considers his team of Rock Pokémon to be what he refers to as a "wall", or a difficult challenge to overcome, using their incredible jumping abilities and Rock Tomb to truly test his opponents.
Onix is Grant's first known Pokémon, which he used in a battle against Viola's Surskit at the Battle Chateau. Despite Surskit creating its signature ice battlefield to aid its speed, Onix was able to turn the tables on the Pond Skater Pokémon by using its masterful control of Rock Tomb to trap it and Rock Polish to increase its speed, keeping Surskit on the defensive. Eventually, Onix ended the battle by using its powerful Flash Cannon to knock Surskit out. It was seen in flashbacks in A PokeVision of Things to Come! and Coming Back into the Cold!.
Onix reappeared in Climbing the Walls! as the first Pokémon Grant used in his Gym battle against Ash; it went up against Froakie. Onix attempted to keep up with the Bubble Frog Pokémon, but Froakie's speed, in combination with Double Team, confused Onix. This left it open to attacks, which eventually allowed Froakie to knock it out with Water Pulse.
Tyrunt was the second Pokémon used by Grant in his Gym Battle against Ash. Tyrunt, unlike Froakie, was quick, and while Froakie was able to dodge Rock Tomb, it was easily overpowered by Tyrunt's Draco Meteor. Tyrunt next went up against Fletchling and managed to knock it out easily (but not before taking damage from a super-effective Steel Wing).
Finally, Tyrunt went up against Pikachu, who was able to dodge Tyrunt's attacks and even used the projectiles from Draco Meteor for momentum before managing to wedge a rock in Tyrunt's mouth and finally knocking it out with a direct hit from Thunderbolt.
Grant debuted in PS563. He was first seen in Cyllage City, helping Clemont 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 PS572, Grant found the Cycling Road in ruins after a helicopter was forced to make a crash landing. He got into an argument with the pilot, Cassius, but eventually calmed down after Cassius agreed to pay for the damages.
In PS577, Grant arrived in Laverre City alongside Valerie and Olympia to visit Korrina, who was recuperating from injuries she sustained in a battle with Team Flare. They soon left to have a meeting with the other Kalos Gym Leaders to decide on how to deal with Team Flare. In PS579, Y, Trevor, Tierno, and Shauna joined the Gym Leaders and traveled to Geosenge Town to confront Team Flare. Shortly after they arrived, the group witnessed the ultimate weapon emerging from underground like a flower bud. To prevent the weapon from blooming, the Gym Leaders and Y used their bodies to keep the petals in place by force, but were met with interference by Bryony. The ultimate weapon eventually fired anyway, but the combined efforts of the Gym Leaders and their allies successfully weakened the weapon enough to make it unable to take any innocent lives. Using her newly-obtained Xerneas, Xerxer, Y tried to destroy the ultimate weapon, but was 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 Y and the others with it.
In PS582, 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 PS593, Grant, Ramos, Valerie, Olympia, and Wulfric helped stop Team Flare's attempt to reactivate the ultimate weapon by defeating a group of Grunts that were stationed around Cyllage City. After Team Flare was fully defeated, Grant and his allies met with X and his friends at Lumiose City to congratulate them on their victory.
Aurorus is Grant's first known Pokémon. It was first seen accompanying its Trainer as they patrolled around Cycling Road only to find it in shambles from the crash of Cassius's helicopter. At Geosenge Town, it helped try to keep the ultimate weapon from opening with its weight. Later, it helped repair the damage done by the ultimate weapon firing on Kalos.
Tyrantrum is Grant's second known Pokémon. It was first sent out at Geosenge Town to keep the ultimate weapon from opening as it was being unearthed. With the help of Valerie's Mr. Mime, it was able to stand on the air, but was knocked off by Bryony's Bisharp.
Grant's Japanese Leader title is ワイルド マイルド ロッククライマー.
Grant is the only Kalos Gym Leader who does not use a fully evolved Pokémon outside of the Battle Chateau.
In the games, Grant is also the only Kalos Gym Leader who doesn't use a Pokémon introduced before Generation VI.
In the anime, Grant made his debut exactly five (aired) episodes before his Gym battle against Ash, with the aforementioned Gym battle episode being the first to have its air date moved forward due to the postponement of the episode intended to air before it. Coincidentally, Grant shares this trait with Burgh.
Grant is the only single Gym Leader who uses Pokémon with identical levels in a Gym battle.
Grant shares his Italian name with Wally: they both go by the name of Lino.