DARK monsters in the CCG are a powerful Attribute. Dark tends to focus on Destruction (Unlike LIGHT) as well as RFG. They might have high ATK powers and swarming capabilities too. Archetypes include Mirrors and Supreme.
Their Field spell is Dimension of Despair. Their searcher is Corrupted clown. Some good DARK support cards include Dark Vibes, Black Shadow Dragon, Dark Chaser, Shadow Searcher and Soul Seller. Cards that go along with the general DARK strategy are Dark Realm Cat, Penance Master and Pneumamorpher.
(NOTE: Corrupted clown was not capitalized when we made it so we have to use lower case "c" for clown for it to link.)