Getting ahold of a Legendary Pokémon is one of the most satisfying aspects of any Pokémon game. Dialga or Palkia can be obtained in either Pokémon Brilliant Diamond or Pokémon Shining Pearl, but it won’t be simple. To begin, one must first overcome several difficulties and conflicts.
Here’s how you can conquer and capture Palkia, and Dialga.
How to capture Dialga and Palkia in Brilliant Diamond and Shining Pearl?
Dialga and Palkia will be out of your reach until you complete a few tasks first. Do this, and this, and this, and this and you’re all set.
Defeat the first seven gyms
Cyrus, the head of Team Galactic, will abduct the Lake Trio — Azelf, Uxie, and Mesprit — after he defeats Candice at the Snowpoint Gym. They will be taken to The Team Galactic Secret base in Veilstone City.
Fight your way through Team Galactic’s headquarters
Navigate your way throughout Team Galactic’s headquarters in Veilstone City. Cyrus will come across you at some point and you’ll have to face him. He will grant you the Master Ball once you beat him, which you can use on Palkia or Dialga.
Find and defeat 1st Commander Saturn in combat. Then, hit the yellow button at the top of the room to release the Lake Trio from their restraints. Hurry to the green warp if you wish to get out of here fast. Get 50 Ultra Balls before continuing to the next phase, if you don’t yet have them.
Head to Mt. Coronet
Defeat Team Galactic grunts as you make your way through the maze-like passages. You’ll eventually reach the Spear Pillar part of Mount Coronet’s summit. If you haven’t previously done so, I recommend going to the menu, selecting Settings, and disabling autosave. Then hit R in the menu to manually save your game. Once you’ve dispatched the two remaining Galactic Grunts standing in your way, you can proceed.
Defeat Mars & Jupiter
Mars and Jupiter will become enraged and start a battle. You’ll be able to take on Team Galactic with them when your adversary appears out of nowhere. You’ll begin to see more of Dialga and Palkia after defeating Mars.
Defeat Cyrus (again)
Cyrus has gone completely bonkers and will do whatever it takes to keep you from deterring him. To get him to depart, you need to defeat him.
Catch Dialga or Palkia
Professor Rowan arrives and informs you that the only way of stopping Dialga or Palkia is to catch them. You could use Master Ball to catch Dialga or Palkia if you’d like. However, I recommend that you reserve it for a unique Pokémon like Azelf, Mesprit, or Uxie.
If you insist on keeping your Master Ball, be sure to carry lots more Ultra Balls with you. It may cost you up to 40 attempts to trap one of these Legendary dragons.