the people who use Fire Pokémon
(Japanese name: Katsura)
Blaine is the main Fire Pokémon trainer of Red, Blue, and Yellow. He is the Gym Leader of Cinnabar Island, and he gives out the Volcano Badge after you defeat him. Of course, the first thing you have to do is find the key to the Gym in the Cinnabar Mansion. You also have to answer questions to get to each trainer. You don't have to fight a Trainer in the Gym if all the answers are correct. But it's a loss of experience, so I'd throw the question every time.
In Red/Blue, Blaine has a level 42 Growlithe, a level 40 Ponyta, an Level 42 Rapidash, and a Level 47 Arcanine. In Yellow he has a level 48 Ninetales, a Level 50 Rapidash, and a Level 54 Arcanine. When I ripped through his Gym, I either used a Vaporeon or a Blastoise. Made it nice and easy. When you whoop him, you get the Volcano Badge (which boosts your Pokémon's special) and TM 38, which gives you Fire Blast.
You see good old Blaine in Gold and Silver again, only with new Pokémon. He's not on Cinnabar--seems the volcano there blew and he's now chilling on Seafoam. (Seafoam--chilling--hehehe....okay, it was a bad pun.) So he lives alone in a cave off Seafoam, upset about this. Of course, this means Articuno is not there anymore. He's alone, so he's he only one you fight. He comes out with a Level 54 Magmar, Level 50 Rapidash, and a level 45 Magcargo. I didn't have my Vaporeon traded over at the time, so I just used my Suicune.
And of course, he's back in FireRed/LeafGreen, falling to Vaporeons and Suicunes the Pokémon world over.
Japanese name: Karin
The only person who has a Fire Pokémon (with the exception of Lance, who I don't like =P) is Karen, a new member of the Elite Four. (I at first guessed that Agatha died and joined her Pokémon in the great Beyonder, but she's in FireRed/LeafGreen so...no.) She's really a Dark trainer, but she has the dark/Fire Houndoom! Now I love Houndooms, but that sucker is EVIL! Stupid Crunch...Once my Suicune was high enough, I Surfed it and watched it drop.
Japanese name: Asuna
Flannery is the new Gym Leader on Ruby/Sapphire. She has taken over from her grandfather, and only wants to be as good as he was. Her Gym, located in Lavaridge Town, is full of Fog. All over the place. And you fall in holes, and get launched back up, and It's very annoying. Anyways, when you get to her she's all ready to fight. She has three Pokémon--two level 26 Slugmas and a level 28 Magcargo. Bad girl! Get better Pokémon! Anyways, she gets easily beaten, and then she hands over the Heat Badge which lets you use Strength outside of battle, and TM 50, Overheat.
Japanese name: Magma-Dan
Who needs Team Rocket when you've got villains that are all about the fire? Team Magma is on your side in Sapphire and against you in Ruby. Their leader is Maxie, and they fight with a mix of Poochyenas and Numel/Camerupts. You fight with them/against them until the other side screws things up at Mt Pyre, and then you have to go save the bloody world. Stupid villains, fucking shit up.