Seems like yours Water team really needs a few Kamihime, the issue with running Belphegor + Gabriel is that you won't be near the 50% Debuff Cap, or even the 40% you can get to with two 20% Debuffs, you'll be at a miserable 27% which doesnt cut it at all, hell a single Kamihime like Amon Unleash Covers 25% by herself, regardless of that Dagon is a really nice girl that I can't stop recommending if you need to cover a spot.