To access the Pokémon Brilliant Diamond and Shining Pearl post-game, you’ll need to unlock the National Pokédex. Our National Pokédex guide will explain how to unlock the National Pokédex and find some missing Pokémon that may be preventing you from finishing it.
What does the National Pokédex unlock?
Having the National Pokédex unlocks more Pokémon in the Grand Underground, like starter Pokémon from previous regions. It also unlocks the full post-game island. You can head over to the top right island after beating the Pokémon League, but you won’t be able to go anywhere until you have the National Pokédex. You also need it before you can grab some Legendary Pokémon.
How do I unlock the National Pokédex?
To upgrade to the National Pokédex, you need to see every Pokémon in the Sinnoh region. (Note: You have to just see them, not catch them.) You also need to beat the Pokémon League. Once you do this, you can head back to Professor Rowan’s office in Sangem Town and a cutscene will play, upgrading your Pokédex in the process.
Where do I find these leftover blank spots?
If you battle every trainer your journey, you will see all but a few Pokémon. The exceptions to this are Drifloon, Riolu, Mesprit, Uxie, Azelf, and Dialga or Palkia (depending on your game version).
You can find Drifloon at the Valley Windworks on Fridays.
Riolu is hatched from an egg that Riley gives you on Iron Island. To get to Iron Island, you’ll need to talk to the sailor in Canalave City and take his boat.
Mesprit, Uxie, and Azelf are all found in their respective lakes. Once you interact with Uxie and Azelf, battle with them will begin. Interacting with Mesprit makes it flee, but it will still register in your Pokédex as seen.
To see Dialga or Palkia, you’ll need to go talk to Cynthia’s grandma in Celestic Town. She’ll show you a book that has the Legendary that doesn’t come with your game version, and it will get marked as seen.
If you’re missing many other Pokémon, we recommend backtracking any routes you may have skipped for trainers you might have missed. Some routes in the game, like route 212, are completely skippable.
It’s also possible that you may be able to battle trainers online with these Pokémon to register them as seen in your Pokédex, but we haven’t been able to test this ourselves.