Capturing Legendary Pokémon is always an exciting moment in any of the Pokémon games. Depending on whether you are playing Pokémon Brilliant Diamond or Shining Pearl, you'll get Dialga or Palkia, but it won't be easy. There are a few challenges and battles to fight through first. Here's what you need to do to beat and capture Dialga and Palkia.
Note: This guide contains spoilers for the ending of Brilliant Diamond and Shining Pearl.
Fight gym leaders and the Elite Four
There are eight gym leaders and the Elite Four to defeat in the Sinnoh region, including the reigning Champion, Cynthia. Take them all down by leveling up the best Pokémon team you can create.
How to capture Dialga and Palkia in Brilliant Diamond and Shining Pearl
There are a few things you'll need to do before you have a chance at capturing Dialga or Palkia. Here's what you need to do.
1. Defeat the first seven gyms
After beating Candice at the Snowpoint Gym, Team Galactic's leader, Cyrus, will capture the Lake Trio — Azelf, Uxie, and Mesprit — and take them back to The Team Galactic Hideout in Veilstone City.
2. Fight your way through Team Galactic's headquarters
Head to Veilstone City and make your way through Team Galactic's building. Eventually, you'll run into Cyrus and will have to battle him.
Once you've defeated him, he'll give you the Master Ball, which you might want to use on Dialga or Palkia.
3. Defeat Saturn
Locate 1st Commander Saturn and defeat him in battle. Then press the yellow button in the top center of the room to free the Lake Trio. You're going to want to get out of here quickly, so run to the green warp. If you don't already have 50 or so Ultra Balls on you, run to the store and grab some before moving on to the next step.
4. Head to Mt. Coronet
Head through the maze-like tunnels defeating Team Galactic grunts along the way. Eventually, you'll make your way to the Spear Pillar portion atop Mt. Coronet. I suggest going into the menu, accessing Settings, and turning off autosave if you haven't already. Then manually save your game by pressing R in the menu. Defeat the last two Galactic Grunts waiting for you here and the walk forward.
5. Defeat Mars & Jupiter
Team Galactic's leaders have gathered together and are ushering in the return of Dialga if you have Diamond or Palkia if you're playing Pearl. Eventually, Mars and Jupiter will want to fight. Out of nowhere, your rival shows up, so you can fight Team Galactic alongside them. After beating Mars, Dialga or Palkia will start to appear.
6. Defeat Cyrus (again)
Cyrus has reached ultra crazy at this point and will battle you to prevent you from stopping him. Defeat him to make him leave.
Catch Dialga or Palkia
Once that's done, Professor Rowan shows up and tells you the only way to stop Dialga or Palkia is to capture them. You can use the Master Ball to capture Dialga or Palkia if you feel so inclined. But I recommend you save it for one of the other either one of the Legendaries at Ramanas Park or the Lake Trio Azelf, Uxie, or Mesprit.
If you choose to save your Master Ball, make sure to bring plenty of Ultra Balls into battle. It might take you upwards of 40 throws to catch these Legendary dragons.
WARNING: If you defeat Dialga or Palkia without capturing them, the game will continue on. As such, you should turn off autosave and manually save just before the battle in case something goes wrong. That way, you can restart the game and enter the Legendary battle again if you have to. This can also be a way to shiny hunt for a shiny Dialga or shiny Palkia.
How to get the other Legendary Pokémon
If you only own either Brilliant Diamond or Shining Pearl, the only way to get the other Legendary Pokémon is by trading with someone. You can either use the Union Room to trade or can dive into the Pokémon HOME trading to get the Pokémon you need.
Legendary trainer
With Palkia or Dialga in your Poké Ball, you're ready to move on and take on the final gym leader and the Elite Four. While you could use these Legendary Pokémon for those battles, other Pokémon will give you a better advantage during those fights.
