It seems OP wants a generic, good for most content, team for each element.

For water, the duo of Ryu-Oh and Vohu Manah would be everything you need for debuffs (-50% Def and, against Fire, -50% Atk; also a BP). I find it odd the duo isn't more recommended, but maybe is it because they make the likes of Snow Raphael, Cthulhu, Nike Unleashed, Water Cybele, with their Def debuff, less necessary? Then I'd round the team with Shiva (AW) and either Asherah or Ea (AW) for easier content, and Februus, Poseidon (AW) or Aphrodite against harder ones...