I have a pretty decent water team, but recently been feeling like I should be swapping someone out for someone in my sub pool but can't decide if it's worth it or not or if I should use the water gacha to try for Cthulu or Ea or something. Anyway current main team is Arthur, Belphegor, Aphrodite, Nike, and Ryu-Oh. Currently sitting on sub are kikuri-hime and nodens. Adding nodens would be nice for HOT but don't see that being beneficial overall, but Kikuri-Hime is what's been bugging me. Belphegor is super nice due to her rage-down skill and atk/def up/down and for being able to extend stun duration so don't see myself tossing her for kikuri-hime, but at the same time want nike + kikuri-hime for perma def-up, which would mean tossing belphy. I've been thinking of swapping nike for kikuri-hime as the 750 heal isn't that useful when I already have aphrodite and I feel like the burst-up would be nice, but not really sure if that's worth it.

Obviously somewhat situational and I need to work on my eidolons and weapons a lot still so not a big thing atm, but was wondering what other people thought. The only other note-worthy water kamihime I have is oto-hime for her fire null ability, but don't think that warrants a primary spot. Also once I get mordred (still a ways away only have 130 SP) do you think it would be worth using Mordred + Ryu-Oh as they both add a turn for special attack or w/e that's called?