Pokémon Masters 8 came out in July of 2022, with a recent battle between Dragon masters Cynthia and Iris giving both competitors some amazing highlights.
Dragon isn't the only type with multiple master trainers in the anime and games. In fact, every type has multiple master trainers that specifically specialize in that type. Some of the best trainers in the entire series are type specialists, with even a few Pokémon League champions having three or more Pokémon of the same type on their teams.
Fire - Flint
Flint is the best friend of gym leader Volkner and a powerful Elite Four member in his own right, and he's arguably the top fire specialist in the games.
While fans sometimes make fun of Flint for having multiple non-Fire types on his team, specialists don't necessarily have to use Pokémon of the same type exclusively. As long as the majority of Flint's team is Fire, he's every bit the Fire-type specialist he says he is.
Water - Wallace
One of Hoenn's champions and gym leaders throughout the history of the games, Wallace is best known for his ace Pokémon Milotic.
There are plenty of strong Water trainers like Wallace's gym leader replacement, Juan, or the powerful Misty. However, Wallace is the only Water specialist to become Champion. Gameplay-wise, he's one of the easier champions, but it isn't a title to take lightly.
Grass - Gardenia
Grass is likely the least represented type when it comes to powerful trainers, unfortunately. This leaves Gardenia, a fairly low-level gym leader, as the type's best representative.
Gardenia can catch players off-guard if they don't have a strong fire type, but largely Gardenia and Erika are sadly the two best representatives for grass in the entire series. However, Gardenia's Roserade is still a solid early-game threat.
Electric - Volkner
Sinnoh's eighth gym leader, Volkner, stands with his best friend Flint as the single best trainer to represent his signature type, Electric.
Volkner and his Luxray make a powerful team, and the Electric specialist isn't to be taken lightly. While Luxray might need buffs to be viable in competitive play, it's more than scary enough in the main series games, thanks to its tremendous attack stat.
Ground - Bertha
Bertha and her Hippowdown can be one of the biggest challenges in the Sinnoh region. While Giovanni is also a Ground trainer, his final team is actually incredibly easy to beat.
Bertha's strongest iteration is in Brilliant Diamond & Shining Pearl, with a Water Absorb Quagsire to counter the Water types that normally dismantle her team. She also has Ice Fang on her signature Hippowdown, allowing it to potentially take out Grass-types.
Poison - Koga
Koga is one of the few trainers to be both a gym leader and make it into a future game for its final challenge. In his case, a member of the Elite Four.
Koga's team in Red & Blue is one of the worst late-game gyms in the history of the franchise, featuring two Koffings that both know Tackle. However, his Elite Four team makes him one of the scarier Johto Elite Four members, with a powerful Crobat that can tear through teams.
Ice - Lorelei
Lorelei is the first Elite Four member in the original games, making her one of two different Ice-type Elite Four members in the franchise.
While there may be another Ice-type Elite Four member, Glacia has arguably one of the worst Elite Four teams in the entire series. Conversely, Lorelei actually has a pretty well-balanced team of solid Ice-types that can do some surprising damage early on in the Elite Four.
Fighting - Bruno
Bruno is the Fighting-type Elite Four member of Kanto, who surprisingly also makes an appearance in the Johto Elite Four.
Bruno has a solid team of Fighting-types, strangely accompanied by Onix in both Elite Four matches, that actually helps cover his Flying weakness decently well. His Machamp can be a serious threat, as are all his Hitmons. Overall, Bruno is a solid Elite Four member.
Dark - Marnie
While there's a powerful Dark-type Elite Four member in Karen, it's still Marnie that has mastered Dark types the best.
Marnie and her Morpeko are one of the game's most iconic Pokémon/Trainer pairs in the series. Still, her most fearsome partner is her terrifying Gigantamax Grimmsnarl. Her brother may be a very strong gym leader, but Marnie is the true Dark-type master in the family.
Psychic - Lucian
Psychic-type master Lucian is the second hardest challenge in Sinnoh, putting up a very tough fight before trainers come face-to-face with Cynthia.
Lucian's Bronzong was so powerful that it was nerfed in Platinum, and the rest of Lucian's team was brutal as well. The Psychic master was a perfect prelude to Cynthia, and he was without a doubt the strongest Psychic trainer that has been released to date.
Bug - Alder
Since he lost to N in Black & White while Iris was the champion for Black 2 & White 2, many fans don't respect how powerful a trainer Alder really is.
The former champion doesn't use exclusively Bug-types, but his team having three certainly makes him a specialist with the type. Escavelier, Accelgor, and his signature Volcarona are the three Bugs that Alder makes use of in the series.
Flying - Kahili
Flying-types don't always get the respect they deserve in the franchise, but they eventually got an Elite Four member in Kahili that was fairly powerful.
The Toucan theme on Kahili's golf club is a fun nod to her ace Pokémon, Toucannon. The Skill Link Toucannon is no joke, and can absolutely tear through teams if the player isn't ready for it. Overall, Kahili is a well-crafted Elite Four member.
Rock - Olivia
Olivia is a Kahuna and member of the Alolan Elite Four at the end of the series. Sadly, she doesn't have much competition as far as Rock-type specialists go.
Most Rock trainers are early game bosses because the type itself isn't especially powerful. Olivia also suffers from a lack of great Rock-types in Sun & Moon. To make matters worse, her ace is Lycanroc's weakest form. Still, she is an Elite Four member.
Ghost - Acerola
Acerola is a Trial Captain who ultimately is a member of the Alolan Elite Four at the end of the games. She's one of the younger Elite Four members in the series.
Acerola's ace Pokémon is her Pallosand, which is ultimately a pretty solid Pokémon with a lot going for it defensively. Acerola is one of the stronger members of the Alolan Elite Four, with a pretty balanced team of ghosts that makes up for her Dark weakness.
Normal - Whitney
Along with Grass, Normal is one of the least-loved types in terms of boss battles. While Norman may appear later in the game, Whitney presents a bigger challenge at the time.
Whitney's Miltank is a story of legends, and the building rollout that it presents can tear teams apart. However, the Miltank is all that Whitney has going for her in her team of two. Fortunately, her post-game rematch team is pretty powerful.
Dragon - Iris
Iris is highlighted far more in the anime than in the games, but she's still a gym leader and eventual champion with all of Unova supporting her in her journey.
Iris's ace is Haxorus, arguably the best mono-Dragon in the games. In the current Masters Eight arc in the anime, Iris and Haxorus were even able to put up a fight against the legendary champion Cynthia and her trademark Garchomp.
Steel - Steven
Steven Stone is a brilliant archeologist, the Hoenn Champion, a mega stone master, a terrifying secret boss, and easily the most powerful Steel-type user.
Steven has the unfortunate task of being Ash's first matchup in the Masters Eight Tournament in the anime. Steven will remain the best Steel-type specialist in the franchise regardless of how the matchup ends, as his Mega Metagross is one of the most powerful partners there is.
Fairy - Bede
Along with Marnie, Bede serves as part of a pseudo-Elite Four in the later stages of Sword & Shield. Although, technically he just breaks in and challenges the player.
Bede's Gigantamax Hatterene makes for a tricky opponent, and they have the potential to do some serious damage. Opal and Mina are also powerful Fairy-type trainers, but the crown goes to Bede's team of surprisingly scary Fairy-types.