Part 5: Pastoria Gym
Now onward to Pastoria Gym... Well almost. Lucas needs our help so head to the Galactic Warehouse at the northwest part of town and take out the Galactic Grunts. After they will return Lucas' Pokedex and Looker will take you into the warehouse. Inside is HM02 Fly, so take it and teach it to your Flying-type Pokemon; this move allows you to fly to towns you have already visited.
Head now down to Route 214 and battle the trainers here. Be sure to stop at the Ruin Maniac's cave to get TM28 Dig. If you capture all the Unown (A-Z) at Solaceon Ruins, he will dig through the entire wall allowing you to get the Rare Candy above Solaceon Ruins. You'll also gain the ability to capture ! Unown and ? Unown.
Head south to Valor Lakefront. Help the woman who lost her Suite Key (which is near the south gate) and deliver it back to her to get the White Flute. Head into the Seven Stars Restuarant to take part in Double Battles with people to gain more experience. After you do that, visit the house to the northwest of the south gate and talk to the clown to get TM92 Trick Room. Continue to Pastoria City, finding TM40 Aerial Ace behind a cracked rock on the west side of the beach.
In Pastoria, heal up at the Pokemon Center. Head to the Great Marsh if you want to collect some Pokemon. When you reach the Pastoria Gym, Barry will challenge you to a battle.
Barry (if you chose Turtwig as a starter):
After beating him, take on the Pastoria Gym! Once you enter the Gym, you'll need to change the water levels of the gym, similar to Zelda's water dungeons. Step on switches to change the water level and navigate the gym to reach Gym Leader Wake!
• Rock Tomb
• Water Pulse
• Ice Fang
• Aqua Jet
After defeating him, you will gain the Fen Badge and TM55 - Brine.