Where do you get a dusknoir in Pokemon diamond?

Answer 1

there are two indirect ways

1 migrate dusclops off ruby, sapphire or emerald or

2 find dusknoir in route 224. You can reach it by going to victory road. Use the north exit

and go to a cave in the right. there you will meet a girl named Marley or who she is then

join her until you find an opening. There she leaves, so go outside. you will find grass, so use the pokeradar. You will eventually find dusclops.

Give him the reaper cloth, then trade to another game e.g. pearl or platinum. Then trade back. You get a dusknoir!