Kabu is the third Gym Leader of the Galar Gym Challenge and the one many challengers stall against. His Gym team is Ninetales, Arcanine and Centiskorch, and the Centiskorch comes out last as a Gigantamax Pokémon. Before the battle, the Gym mission has the player earn points by catching or defeating the Vulpix, Litwick and Sizzlipede living in the stadium's tall grass. Beating him earns the Fire Badge and TM38, Will-O-Wisp.
His backstory is written on his League Card: a Trainer invited from Hoenn who came close to the Championship several times, tried a no holds barred style that did not work, even slipped to the minor division, and regained his confidence after a strong battle against Leon. The player first meets him in Galar Mine No. 2, where he drives off a pair of Team Yell Grunts. His Japanese name mixes the words for turnip, fire and kabuto, the Japanese helmet whose shape appears in his Gym logo.
Kabu was the first Gym Leader from before Generation IX to appear in Pokémon Horizons: The Series. He shows up at the end of The Bittersweet Truth eating at the Motostoke Battle Café, and in the next episode Liko and Roy find him at Motostoke Stadium to ask about the Black Rayquaza. He puts them through a training session that uses basic attacks to light and douse the flames of a group of Litwick, then pairs with his apprentice Wakaba for a Tag Battle in which his Centiskorch overwhelms Sprigatito and Fuecoco. He returns in Fiery Galarian Moltres, investigating a collapse at the Galar Mine.
His card run opens in Darkness Ablaze (August 14, 2020) with an Uncommon Supporter (#163) illustrated by take, who also designed the character, and an Ultra Rare full art version (#186) illustrated by Hitoshi Ariga. Champion's Path reprinted the Uncommon that September (#55, by take) and added a Secret Rare (#77, also credited to Ariga). Two years later, on September 9, 2022, the Lost Origin Trainer Gallery closed his run with an Ultra Rare (#TG26) illustrated by Hideki Ishikawa.
All five cards are the same Supporter in different rarities, so his run is small and easy to map: two Uncommons by take, two higher rarity versions credited to Ariga, and one Trainer Gallery card by Ishikawa. The same Trainer Gallery also printed Centiskorch V and Centiskorch VMAX (TG14 and TG15), which Bulbapedia files as cards of Kabu's Pokémon, even though neither carries his name.
His first English card, an Uncommon Supporter illustrated by take.
The Ultra Rare full art version of the same Supporter, illustrated by Hitoshi Ariga.
The Uncommon reprint from Champion's Path, again illustrated by take.
A Secret Rare from the same set, credited to Hitoshi Ariga.
An Ultra Rare closing his card run in 2022, illustrated by Hideki Ishikawa.
He is the Gym Leader of Motostoke Stadium in Galar, specializing in Fire type Pokémon and awarding the Fire Badge. He was originally a Trainer from Hoenn.
Centiskorch, the last Pokémon he sends out in his Gym battle, where it Gigantamaxes. It is also his only known Pokémon in Pokémon Horizons.
A single Supporter card, Kabu, printed five times across Darkness Ablaze, Champion's Path and the Lost Origin Trainer Gallery between 2020 and 2022.
No card carries "Kabu's" in its name. The Lost Origin Trainer Gallery Centiskorch V and Centiskorch VMAX are associated with him, but they are printed as ordinary Centiskorch cards.

GYM LEADER
5 Trainer cards · 0 partner Pokémon
Kabu is the Fire type Gym Leader of Motostoke Stadium in Pokémon Sword and Pokémon Shield, a veteran invited to Galar from Hoenn whose Gym battle ends with a Gigantamax Centiskorch. His single Supporter card was printed five times between Darkness Ablaze (2020) and the Lost Origin Trainer Gallery (2022).
No published index yet — too few of Kabu’s cards trade often enough to strike one.