I currently use Breeze Dancer. Even though it's hard to form a team (I've done so painstakingly), the great thing about her is that her attack, that can range from 300-1200, costs no chakra, unlike the rest. Though I have not used him, Scarlet Blaze is pretty high damage too. In actuality, Midnight Blade is powerful, as is Crimson Fist. The Azure Fang's shark bomb and poison spread is great too, although it costs 20 chakra.