Pokeradar on Route 224.
It's easier just to catch Duskull in the Lost Tower at Night in Platinum. (Duskull don't appear there in D/P, only Platinum.)
Migrate from Ruby (or Sapphire/Emerald) or trade with Platinum
Route 224 Poke Radar
In Pokemon Diamond and Pokemon Pearl, there is no possible way to catch a Giritina. You can, however, either catch one in Pokemon Platinum or trade with someone who does have one. In Pokemon Pearl, you catch Palkia at Spear Pillar. In Pokemon Diamond, you catch Dialga at Spear Pillar.
You have first to evolve a Duskull into a Dusclops and then trade it while holding a Reaper Cloth.
the route between solaceon town hearthome city(at night)
route 224, found with Pokemon radar. AT NIGHT!
Use PokeRadar on Route 224. There is a 2% chance and the Duskull will be level 23.
Migrate from Ruby (or Sapphire/Emerald) or trade with Platinum
You can find Duskull on Route 224. :)
iI can get 1 for you as long as i get a good Pokemon , im not sure how to catch 1 without cheats or pokesav
Route 224
You can catch Duskull in Pokemon Platinum by going to the Lost Tower that is near Solaceon Town however you can only find it at night.
Turnback cave.
It is very rare but you can catch it at mount Pyre.
On route 224 with the pokéradar.
It evolves into dusclops. hope this helps.
Use Your Pokéradar (obtained with national dex) in route 224 Duskull is rare