There are several Pokémon that you can encounter in your Pokémon Brilliant Diamond and Brilliant Pearl Pokémon adventure. These Pokémon have unique evolution requirements and some are a little difficult than others. For those looking to evolve Dusclops into Dusknoir, you will need to use a specific item. Here's what you need to do to evolve Dusclops into Dusknoir in Pokémon Brilliant Diamond and Brilliant Pearl.
The only way to evolve a Dusclops into Dusknoir is if you have a Cloth Reaper. Unfortunately, among the items for evolution in Pokémon Brilliant Diamond and Brilliant Pearl, Reaper Cloth is relatively difficult to spot. However, there are a handful of ways you can find it. One of the easiest ways to find it is on Route 229. This is a simple location, but the item is a one-time use, so be sure to place it on a Dusclops you want to evolve.
Once you've done that, the next step is to trade Dusclops with another player. When the player receives that Dusclops, he will evolve into Dusknoir when he reaches it. Alternatively, you can ask the other player to send you a Dusclops with a Reaper Cloth and you will immediately receive the Dusknoir without having to make a second trade.