From Bulbapedia, the community-driven Pokémon encyclopedia.
Now that the main game is over, the post-game begins. You'll find yourself in the place where the game originally began: your bedroom in Twinleaf Town. When you go downstairs, your mother will mention that Barry was just over and mentioned something about catching a ship at Snowpoint City.
By now, you should have all 210 Pokémon in your Sinnoh Pokédex sighted and in Sandgem Town you can receive the National Pokédex. If not, you may have missed some. Here is a list of regional Pokémon not owned by a Trainer in Sinnoh.
- Rotom: Found in the TV at the Old Chateau, but only at night.
- Unown: Found in the Solaceon Ruins.
- Manaphy: Picture found in a book on a desk in Mr. Backlot's office in his mansion on Route 212.
- Mesprit, Azelf, and Uxie: Found in their caverns at their respective lakes after the Giratina battle in the Distortion World.
- Dialga and Palkia: Counted as seen during the story event at Spear Pillar.
If you are ready, head to Sandgem Town.
Once Professor Rowan confirms that you have seen all the Pokémon in the Sinnoh Pokédex, Professor Oak will appear. Having heard of your exploits, he will reveal he is bringing components for the National Pokédex and your Pokédex is automatically upgraded. Before he leaves, he'll mention that Pal Park on Route 221 is open. Now you can import Pokémon from the GBA games.
Professor Rowan will then give you the Poké Radar, which will allow you to find non-regional Pokémon in tall grass. For it to work, you need to be standing in tall grass without being mounted on your bicycle. After one use, it takes 50 steps to recharge.
Once you have the National Pokédex, a swarm of Pokémon from a different region will appear on a different Route each day. The house south of Professor Rowan's lab belongs to Lucas/Dawn. Their little sister can tell you which of the swarm Pokémon is currently present.
Fly to Pal Park. Now you're free to go inside! You'll meet Professor Oak who will explain that Pal Park can be used to import Pokémon from Hoenn and Kanto. He gives you the Trainer Counter app for your Pokétch and then leaves for Eterna City. You can import Pokémon from Pokémon Ruby, Sapphire, Emerald, FireRed, and LeafGreen Versions, by inserting the GBA cartridge into the front slot of your Nintendo DS or DS Lite and selecting "Migrate" from the opening menu.
You can get the Kitchen Timer app from a girl in Pal Park's lobby after showing a Snorlax to her and the Color Changer app after receiving the Kitchen Timer and showing a Kecleon to her.
You will need to import Regirock, Regice, and Registeel in order to catch Regigigas in the Snowpoint Temple, unless you have an event Regigigas.
- Main article: Dongle
By playing your Platinum game with a Generation III cartridge inserted in your Nintendo DS or DS Lite's GBA slot, you can make certain Pokémon appear on certain routes and areas throughout Sinnoh. Most of the Pokémon that appear depend on which GBA game is inserted, but Haunter and Gengar will appear in the Old Chateau regardless.
Professor Oak is in the house next to the Gym in the southern part of town. Talk to him and he will give you a Up-Grade and mention that Kanto's Legendary birds Zapdos, Articuno, and Moltres are now roaming around Sinnoh.
At the Pokémon Mansion, talk to Mr. Backlot and he will mention a particular rare Pokémon in his garden. This changes daily, so check back frequently. Occasionally it is a non-regional Pokémon. See this section for a list of the special Pokémon that appear.