I would say Kakuzu, his hearts at the moment they leave their body, they can fly, so Deidara flying out of range with a clay bird, wouldn't be much of an advantage for him, also even if the hearts don't go after Deidara, they can use long range attacks, and they have the other elements to enhaced the power attack of some jutsus; for example he could use Wind and Fire natures to increase the power and range of one jutsu, and Kakuzu also possesses Lighting chakra, which would be a huge advantage over Deidara's bombs. Deidara would win if he uses his nanobombs right of the bag, Kakuzu wouldn't know what's happening, yet Deidara wouldn't use it, because he would be understatimating Kakuzu's abilities because of his own's.