How do you get dusknoir on Pokemon Rumble?

In Pokémon Rumble, you can obtain Dusknoir by defeating it in the game. Specifically, you need to find it in the Toy Palace area during your exploration. Once you defeat Dusknoir, it may drop as a toy that you can then use in your team. Keep in mind that capturing higher-level Pokémon often requires defeating them multiple times to increase your chances.