nobody did answer this but...

who do I use for water teams given I got the following:

R-Undine, Rusalka, Kushinada, Aspara, Circe, Oto-hime, Dagon, Ganges, Abzu
SR- Nike (obviously), Belphegor, Gabriel, Oceanus, Triton, Kikuri-hime, Nodens, Cupid, Enkidu, Atalanta
SSR- Snow Raphael, Aphrodite, Sarasvati

Also has all weapon types except lance, arcane, and gun for water... along with every soul except shingen (about 250 holy soul points total). Also has an MLB tiamat and jack frost so that helps