Some changes introduced in "Devil May Cry 4" are the presence of two playable characters, Dante and Nero, and a slight modification to the shop system. A new currency, Proud Souls, is used to buy new abilities while Red Orbs are used to buy items. Proud Souls are rewarded at the end of missions; the amount varies depending on how well the player performed. The cost of abilities increases with the purchase of other abilities, though all abilities can be sold back for their original price.