Do you like Dialga and Palkia? Would you like to get them on your team? This article will help you! Here's how to catch Dialga and Palkia in Pokémon Platinum. To do this, you will need to defeat the Elite Four.
Steps

Step 1. Talk to Cynthia's grandmother in Celestic Town
She will read you a book about the legendary Pokemon.

Step 2. Buy ultraballs
There is no Poké Mart in Celestique Town, so you will need to buy the necessary items from an elderly couple in the northwest of the city; you can buy duskballs from a man, and ultraballs from a woman.

Step 3. Find the Adamant Orb and Lustrous Orb
They are hidden in a cave of Mt. Coronet at the top of the waterfall.
To get to this waterfall, a Pokémon must have the ability to climb waterfalls (HM Waterfall)

Step 4. Go to the Spear Pillar location
Once you have adamantite and lustrous spheres, you can find dimension rifts at the top of the mountain where Dialga and Palkia are.

Step 5. Save the game
If you accidentally kill or lose Dialga, you will need to reload the game from that location.

Step 6. Enter the blue portal and catch Dialga
As soon as you enter the portal, your battle with Dialga will begin, so be prepared.
- Dialga is a Level 70 Steel-Dragon-Type Pokémon that has the Roar of Time skill. This is an incredibly powerful attack that will most likely make your Pokémon unconscious.
- Use your ultraballs quickly to catch Dialga. You may need a few ultraballs to get this done.
- Once you catch Dialga, you will be transported from the blue rift back to Spear Pillar. You will still see this blue rift, but it will already be empty.

Step 7. Save the game
After you catch Dialga, it's best to save the game so you don't have to catch it again if you have to reboot later.

Step 8. Leave this location and enter it again
This must be done in order for the Palkia portal to appear. When you enter the Spear Pillar location again, you will see a pink portal.
You can save again if you like, but you already saved the game when you caught Dialga. So, if you have to restart the game, you just need to exit and re-enter the Spear Pillar location

Step 9. Enter the pink rift and catch Palkia
As soon as you enter the portal, your battle with Palkia will begin, so be prepared.
- Palkia is a Level 70 Water-Dragon-Type Pokémon that has the Spacial Rend skill. This is an incredibly powerful attack that will most likely make your Pokémon unconscious.
- Use the ultraballs quickly to catch Palkia. You may need a few ultraballs to get this done.
- Once you catch Dialga, you will be transported from the pink rift back to Spear Pillar. You will still see this pink rift, but it will already be empty.
Advice
- For this task, it is recommended to use duskballs and ultraballs.
- To catch Pokémon faster, you can use quickballs, but in this case you will have to make more attempts, since the chance of success is less.
- If you have a masterball, use it right away.
- Save the game before each battle in case you accidentally kill Pokémon.