Visit the house to the east of the Pokémon Center, and talk to the woman inside. She will give you an HP Up when the number of TMs you have collected reaches 10, 20, 35, 50, and 70, and one more when you collect all 95.
Meet Professor Juniper and Skyla
Professor Juniper appears when you walk north past the Pokémon Center. She thanks you for accepting the Pokédex, then evaluates your progress. She rewards you with a Master Ball, the ultimate Poké Ball which will never fail. It cannot be purchased, but can be won as the top prize in Join Avenue's Raffle Shop.
Mistralton Gym Leader Skyla approaches as Juniper is talking to you. The professor had asked to be flown somewhere in her plane, but leaves to visit Celestial Tower first.
Mistralton Cargo Service
The Maid in Mistralton Cargo Service gives you a Heart Scale in exchange for 10 Sweet Hearts. But from February 14 to March 14, you only need to trade five Sweet Hearts to get a Heart Scale.
Talk to the Worker at the east side of the counter when you have a Flying- or Psychic-type Pokémon in your party. He gives you five Net Balls as thanks for helping him load the cargo onto a plane.
Talk to the Backpacker on the southwest part of the runway to add a new Funfest Mission, Big Harvest of Berries.
On the southeast part of the runway, a Pokémon Breeder will pay 1,000 for any of the four types of Mulch. Mulch can be found in Hidden Grottoes, or purchased at Join Avenue's Flower Shop.
Route 7 is thick with patches of tall grass. There are raised walkways everywhere, which can be used to avoid the local wildlife. Celestial Tower is located directly to the north, while Twist Mountain stands off to the northeast.
In the western house, a Hiker would like to trade. If you have an extra Emolga, he would gladly trade his Gigalith for it. Emolga can be found in the rustling grass on Routes 5, 6, and 7. The traded Gigalith arrives holding a Leppa Berry.
Celestial Tower, 1F
Celestial Tower is a five-floor tower that was built as a memorial to departed Pokémon. On the rooftop is a large bell whose tones are said to comfort the spirits.
When you catch up to Professor Juniper on the first floor, she suggests that you try using different items. She hands you a Lucky Egg, which earns 50% more experience points for its holder than normal.
With all the wild Litwick around, your Pokémon could get burned by their Flame Body Ability. Talk to Nurse Dixie on the third floor after defeating her in battle, and she will heal your team to full health.
Ring the Bell
Climb up onto the rooftop platform and ring the bell. The pure tone soothes and comforts the departed spirits. Before you leave, check the west side of the roof to find a hidden Ghost Gem.
The Eastern House
A second house stands halfway through Route 7. The girl in front of the TV will heal your Pokémon to full health, while the old man at the table adds a few entries to your Pokédex. He claims that he has seen Tornadus, Thundurus, and Landorus, but that they looked completely different.
Mom Checks In
When you head east from the house, Mom calls on the Xtransceiver. During the conversation, she tells you that she used to work in the reception area at several different Pokémon Centers. She ends the call by reminding you to visit one right away if your Pokémon are hurt.
As you continue northeast through Route 7, you will soon reach the foot of Twist Mountain. When you climb the stairway to the entrance, you find a burly man blocking the way. He claims that part of the mountain has collapsed, and it's not safe to venture inside right now. Instead, return to Mistralton City to challenge the Gym.
Mistralton City Pokémon Gym Leader: Skyla The High-Flying Girl
The Mistralton Gym is housed in an aircraft hangar, and specializes in Flying-type Pokémon. These birds are typically vulnerable to Electric-, Ice-, and Rock-type attacks. There are three massive turbines in the back of the building, and an occasional gust of wind can knock you back to the entrance. Move when the wind stops, and hide behind one of the walls when it kicks up again.
Defeated, Skyla awards you the Jet Badge, which ensures that all Pokémon of level 70 or less will obey you. She also gives you TM55 (Acrobatics) as a prize.
Juniper returns from Celestial Tower
As you emerge victorious from the Gym, Professor Juniper returns from Route 7. The professor is headed to Mistralton Cargo Service so Skyla can fly her somewhere.
The Kids' Treasure
Visit the house north of the Pokémon Center, and talk to the Youngster inside. Then visit the south end of the runway to find TM40 (Aerial Ace), a treasure that the two kids hid for safekeeping.
Mistralton Cargo Service
Professor Juniper and Skyla are waiting when you enter the Cargo Service building. Talk to Skyla, and Bianca comes rushing in to catch a ride just as the group is about to board the plane. The professor's destination is Opelucid City, but the unstable Twist Mountain prevents anyone from reaching the city by foot from that direction. Instead, Skyla flies the group to Lentimas Town, a tiny mountain village in the eastern part of the region.