Just went down a rabbit hole thinking in addition to Amaterasu, Remilia and Flandre would also have to be wary of a Japanese kami of rain (e.g. Kanako). Japanese rain kami seems to be... dragons? And the definitive one would be Ryūjin. The dragon god. So... Gensōkyō's top patron is a rain god. And vampires are aversive to rain. And Remilia and Flandre live there. 🤔
Oh, and by the way. From what I can tell so far, this Ryūjin thing doesn't seem to be mainstream Shinto? Like, it's the same archetype as Suwako. Kinda native, but also foreign. 'Cause the dragon idea came with Buddhism, that we can trace all the way back to the Indian naga which became dragon when it got to China.
And there's the whole thing with being conflated with Watatsumi – making Toyohime and Yorihime's mom/dad the patron god of Gensōkyō...
