The Dropped Item

When you reach Nimbasa City, you'll be able to find the Dropped Item, which is somebody's Xtransceiver. The moment you get this item, you will receive a call on it from the item's owner stating that they would like the Xtransceiver back. They will request to call you at numerous points, but the locations they call you are very specific, only 15 areas each on a specific tile. These are the exact tiles shown below. After a couple of calls, you will learn that the owner of the Xtransceiver is Yancy/Curtis, one of the presenters of a variety of TV programmes in Unova. Yancy will appear if you're male and Curtis if you're female.

Nimbasa CityRoute 5Route 16Driftveil CityRoute 6
Mistralton CityRoute 7Lentimas TownUndella TownRoute 13
Route 14Lacunosa TownRoute 12Route 11Route 9

Calling them

Once you have had 10 phone calls, they will call you and arrange to meet in Nimbasa City. They will meet you outside the Ferris Wheel and talk to you there. After that, they will register themselves in your Xtransceiver, however they will only appear in certain areas randomly, the same areas as above, but not limited to a single tile.

As you call them, you will have many conversations about a variety of subjects. On the 30th call they'll tell you they want to meet at Nimbasa City where they'll ride the Ferris Wheel with you. Call them to total 50 times, in the 40th call they'll be 'SOUND ONLY', in the 50th call they'll be wearing their work clothes, and cut the line in a second or so.

Trades

Once you have called them 51 times, you can meet them outside of the Ferris Wheel where they will trade. They have a variety of Pokémon, whose species depends upon the gender of the character. All these Pokémon have their Hidden Abilities and most aren't available in the Unova Region. You can repeat trades one a day, even repeating the species of the Pokémon.

Yancy - If you're Male

ニャース
Level 50
OT:Yancy
ルリ
ID:10303
Ability:Unnerve
Hold Item:

Rare Candy
??? Nature.
Date Received. Link Trade. Apparently received at Level 50
Nasty Plot
Assurance
Captivate
Night Slash
 
Trader requests any Pokémon
ソーナンス
Level 50
OT:Yancy
ルリ
ID:10303
Ability:Telepathy
Hold Item:

Ragecandybar
??? Nature.
Date Received. Link Trade. Apparently received at Level 50
Counter
Mirror Coat
Safeguard
Destiny Bond
 
Trader requests any Pokémon
ラルトス
Level 50
OT:Yancy
ルリ
ID:10303
Ability:Telepathy
Hold Item:

Lava Cookie
??? Nature.
Date Received. Link Trade. Apparently received at Level 50
Future Sight
Charm
Hypnosis
Dream Eater
 
Trader requests any Pokémon
タテトプス
Level 50
OT:Yancy
ルリ
ID:10303
Ability:Soundproof
Hold Item:

Old Gateau
??? Nature.
Date Received. Link Trade. Apparently received at Level 50
Endure
Metal Burst
Iron Head
Heavy Slam
 
Trader requests any Pokémon
サイホーン
Level 50
OT:Yancy
ルリ
ID:10303
Ability:Reckless
Hold Item:

Rare Candy
??? Nature.
Date Received. Link Trade. Apparently received at Level 50
Bulldoze
Chip Away
Take Down
Drill Run
 
Trader requests any Pokémon
カラナクシ
Level 50
OT:Yancy
ルリ
ID:10303
Ability:Sand Force
Hold Item:

Old Gateau
??? Nature.
Date Received. Link Trade. Apparently received at Level 50
Rain Dance
Body Slam
Muddy Water
Recover
 
Trader requests any Pokémon
クチート
Level 50
OT:Yancy
ルリ
ID:10303
Ability:Sheer Force
Hold Item:

Lava Cookie
??? Nature.
Date Received. Link Trade. Apparently received at Level 50
Baton Pass
Crunch
Iron Defense
Sucker Punch
 
Trader requests any Pokémon
ミカルゲ
Level 50
OT:Yancy
ルリ
ID:10303
Ability:Infiltrator
Hold Item:

Old Gateau
??? Nature.
Date Received. Link Trade. Apparently received at Level 50
Sucker Punch
Nasty Plot
Memento
Dark Pulse
 
Trader requests any Pokémon
カビゴン
Level 50
OT:Yancy
ルリ
ID:10303
Ability:Gluttony
Hold Item:

Rare Candy
??? Nature.
Date Received. Link Trade. Apparently received at Level 50
Body Slam
Block
Rollout
Crunch
 
Trader requests any Pokémon
ヒメグマ
Level 50
OT:Yancy
ルリ
ID:10303
Ability:Honey Gather
Hold Item:

Ragecandybar
??? Nature.
Date Received. Link Trade. Apparently received at Level 50
Charm
Rest
Snore
Thrash
 
Trader requests any Pokémon
パッチール
Level 50
OT:Yancy
ルリ
ID:10303
Ability:Contrary
Hold Item:

Lava Cookie
??? Nature.
Date Received. Link Trade. Apparently received at Level 50
Teeter Dance
Psych Up
Double-edge
Flail
 
Trader requests any Pokémon
トゲピー
Level 50
OT:Yancy
ルリ
ID:10303
Ability:Super Luck
Hold Item:

Ragecandybar
??? Nature.
Date Received. Link Trade. Apparently received at Level 50
Teeter Dance
Psych Up
Double-edge
Flail
 
Trader requests any Pokémon

Curtis - If you're Female

マンキー
Level 50
OT:Curtis
テツ
ID:54118
Ability:Defiant
Hold Item:

Rare Candy
??? Nature.
Date Received. Link Trade. Apparently received at Level 50
Cross Chop
Thrash
Punishment
Close Combat
 
Trader requests any Pokémon
ソーナンス
Level 50
OT:Curtis
テツ
ID:54118
Ability:Telepathy
Hold Item:

Ragecandybar
??? Nature.
Date Received. Link Trade. Apparently received at Level 50
Counter
Mirror Coat
Safeguard
Destiny Bond
 
Trader requests any Pokémon
ラルトス
Level 50
OT:Curtis
テツ
ID:54118
Ability:Telepathy
Hold Item:

Lava Cookie
??? Nature.
Date Received. Link Trade. Apparently received at Level 50
Future Sight
Charm
Hypnosis
Dream Eater
 
Trader requests any Pokémon
ズガイドス
Level 50
OT:Curtis
テツ
ID:54118
Ability:Sheer Force
Hold Item:

Old Gateau
??? Nature.
Date Received. Link Trade. Apparently received at Level 50
Ancientpower
Zen Headbutt
Screech
Head Smash
 
Trader requests any Pokémon
サイホーン
Level 50
OT:Curtis
テツ
ID:54118
Ability:Reckless
Hold Item:

Rare Candy
??? Nature.
Date Received. Link Trade. Apparently received at Level 50
Bulldoze
Chip Away
Take Down
Drill Run
 
Trader requests any Pokémon
カラナクシ
Level 50
OT:Curtis
テツ
ID:54118
Ability:Sand Force
Hold Item:

Old Gateau
??? Nature.
Date Received. Link Trade. Apparently received at Level 50
Rain Dance
Body Slam
Muddy Water
Recover
 
Trader requests any Pokémon
ヤミラミ
Level 50
OT:Curtis
テツ
ID:54118
Ability:Prankster
Hold Item:

Lava Cookie
??? Nature.
Date Received. Link Trade. Apparently received at Level 50
Shadow Claw
Power Gem
Confuse Ray
Foul Play
 
Trader requests any Pokémon
ミカルゲ>
Level 50
OT:Curtis
テツ
ID:54118
Ability:Infiltrator
Hold Item:

Old Gateau
??? Nature.
Date Received. Link Trade. Apparently received at Level 50
Sucker Punch
Nasty Plot
Memento
Dark Pulse
 
Trader requests any Pokémon
カビゴン
Level 50
OT:Curtis
テツ
ID:54118
Ability:Gluttony
Hold Item:

Rare Candy
??? Nature.
Date Received. Link Trade. Apparently received at Level 50
Body Slam
Block
Rollout
Crunch
 
Trader requests any Pokémon
ゴマゾウ
Level 50
OT:Curtis
テツ
ID:54118
Ability:Sand Veil
Hold Item:

Ragecandybar
??? Nature.
Date Received. Link Trade. Apparently received at Level 50
Endure
Charm
Last Resort
Double-edge
 
Trader requests any Pokémon
パッチール
Level 50
OT:Curtis
テツ
ID:54118
Ability:Contrary
Hold Item:

Lava Cookie
??? Nature.
Date Received. Link Trade. Apparently received at Level 50
Teeter Dance
Psych Up
Double-edge
Flail
 
Trader requests any Pokémon
トゲピー
Level 50
OT:Curtis
テツ
ID:54118
Ability:Super Luck
Hold Item:

Ragecandybar
??? Nature.
Date Received. Link Trade. Apparently received at Level 50
Teeter Dance
Psych Up
Double-edge
Flail
 
Trader requests any Pokémon