Kakuzu wins this
--His large scale elemental attacks have the AOE to reach Deidara despite the latters flight,,,
--He can still see deidaras hand seals jus like any ninja,,, and would be able to tell that his raiton mask can counter deidaras clay bombs as its likely that he would be able to decipher this before C4 comes out,,,,
--He has the mobility to evade C1 bombs jus like sasuke,,,,
--His large scale Katon+Fuuton combos can reach deidara as the former can use his long range mode to attack deidara effectively with strings,,,
Deidara however can win this with C0