Complete the Sinnoh Pokedex
Those who want their Pokemon journey to continue will be happy to know that the game doesn’t end after beating the Champion. The “gotta catch ’em all” slogan isn’t just for show here, since completing the Sinnoh Pokedex will actually open up a ton of new content, including areas that didn’t exist in the original Gen IV games.
There are 150 Pokemon to catch (plus a gifted Manaphy to redeem) to fill Sinnoh’s Pokedex. After going through all that trouble, you can speak to Professor Rowan in Sandgem Town to obtain the National Dex, which increases the grand total to 493 possible entries to catch.
Filling up the National Dex should keep you busy for a good amount of time, especially since Pokemon Home isn’t yet compatible with Brilliant Diamond and Shining Pearl. Time to add those entries the old-fashioned way.
Explore Routes 224-230
As mentioned above, several new routes become available to explore after obtaining the National Dex. Routes 224-230 offer their own mini-adventure for those who beat the game, especially if catching new Pokemon is the goal.
The entrance to Route 224 is in Victory Road. There will be a newly opened wall on the right side of the room that connects Victory Road to the Pokemon League building. Route 224 is a dead end, but it should open up into a path leading to Shaymin once an event starts in the future.
You’ll also be able to reach Route 225-230 by taking the ferry from Snowpoint City. You’ll gain access to the Survival Area, Fight Area, Resort Area, and more in the northeastern corner of the Sinnoh map.
Challenge the Battle Tower
While exploring Routes 225-230, you’ll come across the Battle Park as you continue to the right after arriving on the dock. The Battle Tower is located inside the Battle Park and you really can’t miss this enormous building.
As with Battle Towers in previous Pokemon games, this one will let you take on multiple Trainers, including Gym Leaders and other major characters like your rival’s father, Palmer. This tower provides whole new obstacles to overcome after beating the standard Pokemon journey.
There are certain rules and regulations that need to be followed to even the playing field, and you can choose to take on the tower’s single battles, double battles, or Master Class challenge to earn BP for rewards.
Go to Ramanas Park
Ramanas Park is another completely new area in Pokemon Brilliant Diamond and Shining Pearl, and you can get to it after obtaining the National Dex and finishing the game.
This new location will allow you to encounter and catch the legendary Pokemon from previous games and add them to your team. Ramanas Park is found at the end of Route 221. Use Surf to head south from Sandgem Town, then keep right to find a passageway that leads to land.
Finding Slates across Sinnoh and bringing them to Ramanas Park will cause legendaries to appear, so you can catch all of your favorites that existed before Gen IV.
Beat the Elite Four Again
This may sound like a silly or pointless thing to do after beating the Pokemon League one already, but the battles are quite different after the first time through.
Each member of the Elite Four, along with Cynthia, all have different Pokemon in their parties as well as new tactics, items, and higher-level threats to deal with after you become Champion.
In fact, the Trainers will change up their Pokemon two more times after your first win, so it’s worth challenging the Pokemon League two more times after the first victory.
Those are just a few of the major activities that you can experience after beating Pokemon Brilliant Diamond and Shining Pearl, but if you’re still going through the main story and need some pointers, be sure to check out our guide wiki for the remakes.