Walkthrough
After saving Mr. Fuji and obtaining the tea from Brock in Celadon City, you actually will earn access to Saffron City. However, if you would like to prepare for the challenge that awaits you there, you can head south of Lavender Town on Route 12. Route 12 is full of Wild Pokemon and Trainers - the Pokemon blocking the path earlier can now be awoken by using the Pokeflute - and it begins the long path to Fuchsia City. Believe it or not, the fifth Pokemon Gym is in Fuchsia City.
Interactable Pokemon
Snorlax (Pokeflute): Level 34
Wild Pokemon
Grasses:
Pidgey (20%): Levels 31-36
Pidgeotto (20%): Levels 31-36
Bellsprout (15%): Levels 31-36
Weepinbell (15%): Levels 31-36
Krabby (15%): Levels 31-36
Farfetch'd (10%): Levels 31-36
Kingler (5%): Levels 31-36
Grass - Special Spawns:
Chansey: Levels 31-36
Waters:
Tentacool (30%): Levels 31-36
Horsea (30%): Levels 31-36
Magikarp (30%): Levels 31-36
Tentacruel (5%): Levels 31-36
Seadra (5%): Levels 31-36
Sky:
Pidgey (60%): Levels 3-56
Pidgeotto (35%): Levels 3-56
Pidegot (5%): Levels 3-56
Sky - Special Spawns:
Dragonite: Levels 3-56
Charizard: Levels 3-56
Articuno: Levels 3-56
Zapdos: Levels 3-56
Moltres: Levels 3-56
Trainers
Fisherman Ned: Level 27 Staryu
Fisherman Chip: Level 27 Poliwhirl
Fisherman Hank: Level 27 Magikarp, Level 27 Poliwag, Level 27 Seaking
Fisherman Elliot: Level 27 Gyarados, Level 27 Magikarp
Ace Trainer Zach: Level 28 Tangela, Level 29 Onix
Fisherman Andrew: Level 36 Tentacool, Level 36 Kingler
Rocker Luca: Level 36 Electabuzz
Camper Justin: Level 35 Nidoran M, Level 35 Nidorino
Coach Trainer Priya: Level 38 Butterfree, Level 39 Clefable
Obtainable Items
TM50: From Girl In Upstairs Route 12 Gate
Poke Balls: Defeat Fisherman Ned
Poke Balls: Defeat Fisherman Chip
Lure: Near Fisherman Chip
Poke Balls: Defeat Fisherman Hank
Repel: Near Fisherman Hank
Poke Balls: Defeat Fisherman Elliot
Ultra Balls: Defeat Ace Trainer Zach
Ultra Balls: Near Ace Trainer Zach
TM27: On Island South Of Route 12 Gate (Requires Sea Skim)
Poke Balls: Defeat Fisherman Andrew
TM32: From Mr. Dazzling In House South Of Snorlax
Poke Balls: Defeat Rocker Luca
Water Stone: Near Rocker Luca (Requires Chop Down)
Great Balls: Defeat Camper Justin
Awakening: Near Camper Justin
TM59: Defeat Coach Trainer Priya
Max Lure: Within Grass Patch Behind Chop Down Tree
Post Game
Walkthrough
After defeating the Elite Four and starting the Master Trainers Challenge, you will find a number of Master Trainers on Route 12. In total, there will be five Master Trainers to defeat.
Trainers
Swimmer Suzy (Master Trainer): Level 65 Squirtle
Bird Keeper Wyatt (Master Trainer): Level 75 Pidgeot
Lass Vicky (Master Trainer): Level 65 Poliwag
Swimmer Lucy (Master Trainer): Level 75 Seadra
Swimmer Evette (Master Trainer): Level 70 Goldeen