Encounter 1: Petalburg City

Location: Petalburg City

When you first enter Petalburg City Gym, you will encounter Wally for the first time. Wally is just starting his journey and is very timid, and is unsure how to capture Pokémon. At Norman's request, you will take him to find a Pokémon. In Route 102, you will encounter a Ralts and, using Norman's Zigzagoon, Wally will capture it.

Afterwards, he thanks you by giving you the PlayNav for the PokéNav Plus, allowing you to trade with other players.

Encounter 2: Mauville City

Location: Mauville City

When you reach Mauville City, you will find Wally arguing with his father outside the Gym. Wally insists that he is strong enough to challenge the gym, but his uncle is not sure and is worried about him. In order to prove his strength, Wally will challenge you to a battle.

Pokémon Trainer Wally Ralts
Items
Level 17

Synchronize
Attacks:
Confusion
Growl
Double Team
Teleport
Hold Item:
No Item

After defeating him, his uncle gives you HM06, Rock Smash

Encounter 3: Petalburg City

Location: Petalburg City

When you have defeated Norman in the Petalburg City Gym, when you leave you will encounter Wally and his Uncle. Wally will say how much he has grown and his uncle will give you HM03, Surf, as a thanks for inspiring Wally. Wally will then take you automatically to Route 118 in order to proceed.

Encounter 4: Victory Road

Location: Victory Road

As you reach the end of Victory Road, you will encounter Wally again. Wally will say how much he has grown as a trainer and will thank you for your help to get where he is now. He will then challenge you to a battle, with a very well-rounded team. Defeat him and he will give you a Dawn Stone.

Pokémon Trainer Wally AltariaDelcattyRoseliaMagnetonGallade
Items
Level 46Level 46Level 46Level 46Level 48

Natural Cure

Cute Charm

Poison Point

Sturdy

Steadfast
Attacks:
Aerial Ace
Safeguard
Dragon Pulse
Cotton Guard
Attacks:
Sing
Disarming Voice
Charm
Feint Attack
Attacks:
Synthesis
Leech Seed
Petal Blizzard
Toxic
Attacks:
Screech
Discharge
Tri Attack
Flash Cannon
Attacks:
Psycho Cut
Close Combat
Slash
Swords Dance
Hold Item:
No Item
Hold Item:
No Item
Hold Item:
No Item
Hold Item:
No Item
Hold Item:

Galladite
Encounter 5: Petalburg City

Location: Petalburg City

In the Delta Episode, when you get to Petalburg City, you will see Wally being attacked by Team Aqua or Team Magma. This attack has Courtney or Matt depending on your version attacking Wally in order to gain his Key Stone for Mega Evolution. Defeat them and Wally will thank you, but note that his Key Stone has been stolen already, before Courtney/Matt got there..

He gets his Key Stone back at the end of the Delta Episode.

Encounter 6: Battle Resort

Location: Battle Resort

After the Delta Episode, you will encounter Wally when you enter the Battle Resort. He is excited to participate in the battles there, and will run off towards the Battle Maison. Here, you can battle with Wally as a partner, but that's not all. After you have beaten one of the Battle Chatelaines in a Super Battle to gain the trophy, Wally will re-appear in the Battle Maison and will challenge you to a rematch. His team gets stronger as time goes by.

Pokémon Trainer Wally AltariaDelcattyRoseradeMagnezoneGallade
Items
Level 64Level 64Level 64Level 64Level 66

Natural Cure

Cute Charm

Poison Point

Sturdy

Steadfast
Attacks:
Aerial Ace
Safeguard
Dragon Pulse
Cotton Guard
Attacks:
Sing
Disarming Voice
Charm
Feint Attack
Attacks:
Synthesis
Leech Seed
Petal Blizzard
Toxic
Attacks:
Screech
Discharge
Tri Attack
Flash Cannon
Attacks:
Psycho Cut
Close Combat
Slash
Swords Dance
Hold Item:
No Item
Hold Item:
No Item
Hold Item:
No Item
Hold Item:
No Item
Hold Item:

Galladite
Pokémon Trainer Wally RoseradeTalonflameAzumarillMagnezoneGarchompGallade
Items
Level 79Level 79Level 79Level 79Level 79Level 81

Poison Point

Gale Wings

Huge Power

Sturdy

Rough Skin

Steadfast
Attacks:
Shadow Ball
Leech Seed
Petal Blizzard
Poison Jab
Attacks:
Brave Bird
Flare Blitz
Steel Wing
Tailwind
Attacks:
Aqua Jet
Play Rough
Aqua Tail
Iron Tail
Attacks:
Thunder Wave
Discharge
Reflect
Flash Cannon
Attacks:
Dragon Claw
Crunch
Earthquake
Stone Edge
Attacks:
Psycho Cut
Close Combat
Leaf Blade
Swords Dance
Hold Item:

BrightPowder
Hold Item:

Life Orb
Hold Item:

Assault Vest
Hold Item:

Air Balloon
Hold Item:

Rocky Helmet
Hold Item:

Galladite