You're probably wondering how to evolve pokemon in Pokemon Mystery Dungeon DX, because during the story, no matter how high you level up your Pokemon, they cannot evolve. It doesn't happen automatically once they reach a certain level like in the mainline Pokemon games, and there isn't a special method to evolve either. To evolve pokemon you just need to fulfil certain criteria to unlock the ability. Here's all you need to know about how to evolve pokemon in Pokemon Mystery Dungeon DX, along with where to get Evolution Crystals.
How to evolve in Pokemon Mystery Dungeon DX
The short answer is that in order to evolve Pokemon in Pokemon Mystery Dungeon DX, you need to beat the main story. After you see the credits roll and "The End" on your screen, you can return to the town square and find a place called the Luminous Cave has opened by Whiscash's Pond.
Entering the cave will present you with a menu that will allow you to evolve any of your Pokemon – provided they have a Pokemon to evolve into in the first place, of course. There are specific criteria you have to meet depending on the Pokemon though.
When looking at the information screen – if the Pokemon is able to evolve – it'll specify the level it needs to be in order to evolve. For these Pokemon, it's as simple as reaching that level then entering Luminous Cave and evolving them.
Then there's Evolution Crystals. Some Pokemon require an Evolution Crystal to evolve, so read on for everything you need to know about how to get them.
Pokemon Mystery Dungeon DX Evolution Crystals
Evolution Crystals are pink gems that you won't be able to find until you reach the postgame. You can sometimes find them in Kecleon's shop inside dungeons, and there's also a rare chance of finding a floor with no enemies with some Evolution Crystals in a single large room. They can also be obtained as job rewards.
We haven't discovered whether they can be bought from the shop in the town square yet, but will update this if we find they can.
When you've got an Evolution Crystal, evolving the Pokemon works in the same way. Head into Luminous Cave then as long as you've got an Evolution Crystal in your toolbox, you'll be able to evolve one Pokemon for every crystal. Good luck!