Pokédex Rewards

Unlike most of the past games, Pokémon Black 2 & White 2 provides a special gift if you're able to completely fill your Pokédex. Rather than a certificate, these gifts have a substantial impact onto the game.

See All Unova Pokédex

Method:
If you see all of the Pokémon within the Unova Dex, when you go to talk to Professor Juniper, she will notice that you have seen all the Pokémon within the Pokédex and will offer you a Present. This Present is the special Permit item which takes you to the Nature Preserve where loads of rare Pokémon, including a Shiny Haxorus, dwell

Catch All Unova Pokédex

Method:
If you manage to capture all of the Pokémon within the Unova Pokédex, when you go to show Professor Juniper, she will give you the special Oval Charm. This item increases the likelihood that your Pokémon will have eggs when in the Day Care Centre

Picture Name Effect
Oval CharmA mysterious unbelievable charm that when held, makes it easier for the Daycare Man to find eggs. 
Capture All National Pokédex

Method:
Finally, when you manage to capture all the Pokémon in the National Pokédex (not counting event legends) and show it to Cedric Juniper, he will tell you his daughter has a present for you. This present is the special Shiny Charm. This item increases the likelihood that you will encounter Shiny Pokémon. When you have the item in your bag, then the chances of encountering Shiny Pokémon in the wild is increased to 33% of normal, making it a 1 in 2,370.6 chance. If, however, you\'re using the Masuda Method to breed, it increases it from 1 in 1,365.3 down to 1 in 1024.

Picture Name Effect
Shiny CharmA mysterious Shiny Charm that when held, makes it easier to encounter shiny Pokemon.