well, right now i'm looking at 380 holy points (still not enough for masamune, who i need for shingen), and my water kami are as follows:

R- Undine, Rusalka, Kushinada, Aspara, Circe, Oto-Hime, Dagon, Abzu
SR- Nike, Belphagor, Gabriel, Oceanus, Triton, Kikuri-Hime, Nodens, Enkidu, Cupid
SSR- Aphrodite and Saraswati

so aside from a few (like Belphagor, Gabriel, and Aphrodite), not sure who to use...

Hell, given my setup using Mordred, Sol, Raphael, Diana/Uranus, and Tsukiyomi... my light team not only survives better but hits harder than my water one... all I really got is more healing options on water (HP and status recovery wise)