Pokémon Black 2 & Pokémon White 2

Unova Link

The Unova Link is a new, fairly innovative, feature that provides a new way tos hare things with your friends, and make sure you get as much out of the game as possible. There are three different parts to this feature, each with their own features.

Key Link

Features:
The Key Link is the first link system in the game and allows for players to connect between Black 2 games and White 2 games, as well as Black 2 to Black 2 and so forth. During the progress of the game, you will unlock certain keys, these keys will give you a variety of new features in the game from different areas to difficulty shifts.

One of the core aspects of the Key Link feature is that when you unlock the keys, you can send them to your friends regardless of how far through the game they are. As such, if you have a friend who struggles to get through the game, you can send them the Easy Mode key and help them out.

Activation
However, this feature is not just for sending to other players. Once you unlock the keys, you have full access to to their features within your own game, without the need to send them to others. Below are the features that can be unlocked.

Mode Change
Name	Feature	Standard Method of Obtaining
Easy Mode	Lowers the opponent's AI and Pokémon levels	Defeat the Champion
Normal Mode	Standard gameplay	From Beginning
Challenge Mode	Raises the opponent's AI and Pokémon levels	Defeat the Champion
Area Change
Black City - Tower Key	Changes area to Black City	Black 2 Beginning
White Forest - Forest Key	Changes area to White Forest	White 2 Beginning
Ruin Change
Rock Peak Key	Underground Ruins designed for Regirock	From Beginning
Iron Key	Underground Ruins designed for Registeel	Capture Regirock (Black 2)
Iceberg Key	Underground Ruins designed for Regice	Capture Regirock (White 2)

As you load your save file, it will tell you what features you have turned on that deviate from the default.

Click here for further details on Easy Mode & Challenge Mode

Memory Link

Features:
The Memory Link feature allows for your Pokémon Black 2 & White 2 games to collect data from Black & White related to your game . This ranges from superfluous information such as your old trainer name being mentioned in reference to past events, or entire things such as your Musical Props being carried over to Black 2 & White 2

This can be done over local wireless or over the Nintendo WiFi Connection, though it is said that the preferred method is local wireless.

Below is a list of what it affects
A Triple Team: In the Striaton City Restaurant, listen to Cilan, Cress & Chili's emotions.
Different Bones & Dreams: At the NacreneCity Museum, listen to what Bone Specialist Lenora has to say.
Hearts' Desire: At a certain building with a frozen floor in Icirrus City, Brycen awaits.
A New Light: After entering the palace, Drayden is thinking of the past at Opelucid City.
Taking It To The Next Level: After arriving at Lentimas Town, in front of the Mistralton City Gym, Skyla wants to talk about her worries to someone.
White And Black: After you first enter the Pokemon World Tournament, at a certain EX-Team Plasma member's house in Driftveil City, a certain somebody has arrived...
Goodbye, my loved Star: The ownder of the Musical in Nimbasa City is reminiscing.
Meeting Friends, Saying Good-Bye: At a Pokemon Center, a Breeder is thinking about Pokemon.

Click here for further details on unlocks

Nintendo 3DS Link

Features:
The final part of the Unova Link feature is probably to be the more commonly used. This feature allows you to bring in the items and Pokémon you have captured in Pokémon Dream Radar and have them come to your game. This is vital to get Pokémon with their Hidden Abilities as well as the special Therian Formes of Tornadus, Thundurus and Landorus