I decided to split the rain system into an independent mod. It works the same way as the rain feature in Finite Water, except for water refilling - that part is still handled by Finite Water.
Dynamic Rain also provides an interface that lets other mods read the current weather state. Finite Water will use that interface in the next release to refill water bodies based on rain. It's mostly refactoring.
As for lightning on Fulgora, I think it's a great direction for this mod. I'm just not sure about adding lightning damage, because early-game players have no way to protect themselves from it, and that could feel pretty disappointing