Trainer Hill is one of the easier options. All you have to do is run through all four floors of the hill as fast as you can. Basically, the place is full of Trainers to Double Battle, and their Pokémon will be at the level of your Highest Level Pokémon. I say you go there before you try the Battle Frontier, since you're gonna need some serious EV-Training to be able to beat the Frontier Brains. Follow the Guide by Matt Johnson if you wan't to get through it quick.
The Guide:
Tip: While the point of Trainer Hill is to test your Double Battle
prowess, some battles in some modes can be done in Single Battle fashion. Of
course, the battles in anything but Expert Tag Match are easy beyond belief.
NORMAL TAG MATCH
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The blue doo-dahs are ledges to jump. Jump the first two, then jump down the three on the right side. Go right and up. Jump the ledge on the left, then go up and left, around the ledges, fight the Double Battle.
Triathlete Alfonso - Flareon, Pinsir, Magneton
Hex Maniac Alaina - Misdreavus, Claydol, Solrock
On the second floor, go down the left side, then up again. Slide across the
floor, then follow the path. Stupid jump mats. Enter the view of the two.
Black Belt Theodore - Meditite, Heracross, Hitmontop
PKMN Breeder Jayden - Mr. Mime, Plusle, Togepi
On the third floor, go down. Step on the top arrow. Now alternate between
stepping on arrows that point up and arrows that will take you to the other
side of the obstacle in your way. Do this until you reach the top.
PKMN Breeder Salvadore - Vaporeon, Dodrio, Omastar
PKMN Breeder Veronica - Nidoqueen, Ninetales, Charizard
On the fourth floor, position yourself above the fourth slidey tile from the
left and step down, left, down, right, up, left, down, right, directly into a
battle.
Psychic Keenan - Alakazam, Blissey, Grumpig
Aroma Lady Kristina - Tropius, Bellossom, Meganium
Now go right, down, left, up, right, down, left, up, right, up. For winning
this mode, you receive a Great Ball. Wahoo.
VARIETY TAG MATCH
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The first thing you'll see are pink arrows pointing in various directions. Your
job is to make it to the two Trainers in the middle, waste them, and continue.
From the door, go straight down onto the arrow. Then go down, up, left, down.
Gentleman Terrance - Delibird, Clefairy, Pikachu
Lady Elizabeth - Corsola, Starmie, Clamperl
Next floor. Go all the way down, then all the way right. Straight up, then.
Parasol Lady Annabell - Jigglypuff, Jynx, Exploud
Collector Coleman - Illumise, Spheal, Vigoroth
On the third floor, the blue things are ledges and the black tiles make you
slide until you hit a tile that isn't black. Stand on the third yellow tile
from the right and jump. Go right and jump down. Go right, then up, directly
into a Double Battle.
Rich Boy Enrique - Wooper, Poliwag, Psyduck
Lady Colleen - Baltoy, Pineco, Voltorb
Okay. For the final floor, you need to maneuver your way around the obstacles using the arrows. Start by standing between the up arrows on the left and the down arrows on the right, directly above one of the aforementioned obstacles.
Now, step right, down twice, right twice, down four times, right twice, up five
times, left, up, right, up. Have a ridiculously easy battle.
Pokefan Kimberly - Unown K, Unown P, Unown G
Pokefan Francisco - Unown O, Unown L, Unown N
Win here, and you get a Great Ball.
UNIQUE TAG MATCH
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When you get up to the first floor, you'll see two paths to go down. Go all the
way down the one on the right, then go right on the bottom path. Go all the way right and then follow this path to the Trainers.
Kindler Bernard - Magcargo, Rapidash, Moltres
PKMN Ranger Meredith - Sunflora, Venusaur, Tangela
Ascend to the next floor. You'll see pillars that you can walk behind, but no
Trainers. They are hiding behind pillars towards the end. There are no side
paths to take, so simply walk behind the pillars and around the obstacles to
get to them.
Ruin Maniac Abraham - Smeargle (x3)
Tuber Luc - Cubone, Beedrill, Raticate
On the next floor, follow the path. That's all you gotta do.
Youngster Breyden - Charmeleon, Wartortle, Ivysaur
Tuber Aniya - Cleffa, Wynaut, Magby
(Side note: The first group of notes is the first 11 notes of Pallet Town's music, where you begin your adventure in the color games and new color games. Run to hear it correctly. The second batch is Route 101's music.)
On the next floor, you'll see one of the two Trainers. You can fight him separate from the girl if you want. It's probably a lot easier.
Triathlete Stephanie - Houndoom, Stantler, Articuno
Bird Keeper Dane - Sudowoodo, Slowking, Entei
EXPERT TAG MATCH
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Go down the path and up to the Trainers.
Cooltrainer Alfred - Snorlax, Miltank, Ursaring
Psychic Edie - Gengar, Alakazam, Gardevoir
Up to the next floor. Ooh, music tiles!
Cooltrainer Roderick - Swellow, Machamp, Ursaring
Cooltrainer Alicia - Dusclops, Ninetales, Banette
The music tiles play Gym Leader victory music.
You'll have to do the next battle as a Double Battle.
Expert Terrence - Wobbuffet, Exploud, Crobat
Expert Carlotta - Dewgong, Politoed, Marowak
Go around the old person you weren't next to and go to the next floor.
Are you ready?
PKMN Ranger Nora - Forretress, Electrode, Exeggutor
PKMN Ranger Gav - Gengar, Dusclops, Misdreavus
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