Pokémon BDSP Hardest-To-Find Pokémon To Complete Sinnoh Pokédex
Robert Clark
Published Mar 29, 2026
There are 150 Pokémon in Pokémon Brilliant Diamond & Shining Pearl's Sinnoh Pokédex, but some of them are much more difficult to find than others.
In Pokémon Brilliant Diamond & Shining Pearl, players must encounter all 150 Pokémon in the Sinnoh region in order to complete their Sinnoh PokéDex, but some are much harder to find than others. There are plenty of common Pokémon that are easy to find in the wild, and players can fill their Pokédex even more quickly by battling trainers that have rare Pokémon on their team. However, along with rare Pokémon that are much harder to find, there are some Pokémon that only appear under special circumstances, making them easy to miss as players work to complete the last few entries to unlock the National Dex.
Pokémon can be found in grass, lakes, caves, and trainers will encounter them at every turn as they adventure through Sinnoh. Additionally, Brilliant Diamond & Shining Pearl introduced Pokémon Hideaways to Sinnoh’s Grand Underground, and many of the games’ rare and hard-to-find Pokémon can be found in these Hideaway caves. To add a Pokémon’s information to the Dex, however, players only need to battle them once, and while some information will be left out until they’re caught, these encounters still count towards the completion of the Sinnoh Pokédex.
However, the most difficult Pokémon that must be found in order to complete the Sinnoh Pokédex require the right conditions to appear, and players may have to search far and wide to find a Trainer with these rare Pokémon on their teams. Like all core series Pokémon games, there are also version-exclusive Pokémon that can only be obtained in the other version via trading, but all of these Pokémon can be encountered by battling trainers throughout the region to complete their Dex entries. Once trainers encounter all 150 Pokémon, they can take their completed Sinnoh Pokédex back to Professor Rowan’s lab in Sandgem Town to unlock the National Dex.
How To Add Dialga And Palkia To The Sinnoh Dex In Pokémon BDSP
Pokémon Brilliant Diamond & Shining Pearl’s Legendaries, Dialga and Palkia, are encountered at the climax of the game’s main story as players thwart Team Galactic’s leader, Cyrus, at the Spear Pillar atop Mount Coronet. Of course, since each Legendary is exclusive to its own version, players will only have the chance to encounter one of these dragons during their playthrough. Players with the Brilliant Diamond version will be challenged by Dialga, and those who have the Shining Pearl version will face off against Palkia.
However, trainers are able to add the other game’s Legendary to the Pokédex by visiting Cynthia’s grandmother in Celestic Town. After the showdown with Cyrus, she’ll show them a photograph of either Dialga or Palkia depending on the version, which will complete its entry in the Dex. Dialga and Palkia can also be added to the Pokédex via trading, but that requires Trainers to find a friend who’s willing to trade their own version’s Legendary.
Drifloon’s Unique Spawn Makes It Tough To Find In Pokémon BDSP
While Drifloon isn’t technically a rare Pokémon, its unique spawn mechanic in Pokémon Brilliant Diamond & Shining Pearl makes it one of the easiest Pokémon in the Sinnoh Pokédex to miss. Drifloon can only be found outside of the Valley Windworks on Fridays, which means that players have to be at the right place at the right time in order to encounter it since its appearance is dependent on the Switch’s date and time settings. However, players who don’t want to wait until the next Friday comes around can change these settings in the console’s menu to get Drifloon to spawn in Pokémon BDSP.
While players can add Drifloon to the Sinnoh Pokédex by catching or battling it in the wild, there are two trainers in the game who have this Pokémon on their team as well. However, like Drifloon itself, these trainers are also incredibly easy to miss as both of them are inside the Hearthome Gym. When players select the wrong answers to Fantina’s math problems, they’ll encounter a trainer who will offer them another question. If the player gets it wrong, they have to battle, but if they get it right, they’ll miss the opportunity to encounter Drifloon. Once players defeat Fantina and earn their Relic Badge, these trainers will no longer be available to battle, which means that players who pass them by during their gym challenge will have to encounter Drifloon in the wild to complete its Pokédex entry.
Unown Is Only In Pokémon BDSP’s Obscure Solaceon Ruins
The Solaceon Ruins are tucked away on the outskirts of Pokémon Brilliant Diamond & Shining Pearl’s Solaceon Town, and this mysterious, maze-like ruin is pretty easy to miss. However, the Solaceon Ruins are the only location where Unown can be found, and there aren’t any trainers in the Sinnoh region with this Pokémon on their team. So, players will have to explore this area in order to complete their Sinnoh Pokédex.
There are a total of 28 forms of Unown available in the game, and while only one has to be encountered for it to count toward the completion of the Pokédex, players can spend hours running through the Solaceon Ruins to try and collect all of them. Finding the 26 letter-shaped Unown forms in the main part of the ruins will unlock a secret area where the punctuation-shaped forms can be caught. However, players will have to find the hidden entrance to the ruins on Route 214 in order to get there.
Burmy, Wormadam, and Mothim Require Patience In Pokémon BDSP
Encountering a Burmy in Brilliant Diamond & Shining Pearl requires time, effort, and a fair bit of patience as these rare Pokémon only spawn on Honey Trees. By slathering the bark of these special trees with honey and waiting 6 hours in real-time, players will attract a wild Pokémon, but unfortunately, Burmy has a very low chance of appearing, so it will most likely take multiple attempts to find one in the wild. For players who would prefer to skip the Honey Trees altogether, there’s a single trainer in the Eterna Forest with a Burmy on his team.
In addition, both of Burmy’s evolutions are just as difficult to encounter as Burmy evolves into one of two different forms depending on its gender. Female Burmy will evolve into Wormadam, and male Burmy will evolve into Mothim, and since trainers need both to complete the Sinnoh Pokédeex, they’ll have to find, catch, and evolve more than one Burmy. Fortunately, there’s a trainer with Wormadam on Route 214, and another trainer on Route 210 has a Mothim, so players who just want to complete their Dex entries can skip the Honey Trees altogether.
Riolu Must Be Hatched In Pokémon BDSP
In order to obtain Riolu in Brilliant Diamond & Shining Pearl, players have to travel to the Iron Islands and team up with Riley to take down some Galactic Grunts who have been stirring up trouble. This area can be reached by taking the boat from Canalave City, but as an optional part of the game, players may pass it by entirely. After defeating Team Galactic, Riley will present the player with an egg that can be hatched into a Riolu after about 6,000 steps, which players can keep track of with the pedometer app on their Pokétch. Luckily, riding a bike counts as taking steps, which significantly reduces the amount of time it takes to hatch Riolu. Once the egg finally hatches, Riolu’s data will automatically be added to the Sinnoh Pokédex, completing the entry for one of the toughest Pokémon to find in Pokémon Brilliant Diamond & Shining Pearl.
