Darvid (5e Deity)
From D&D Wiki
Alignment. Chaotic Neutral
Divine Rank. Lesser Deity
Darvid is a Norse lesser deity who seems to enjoy finding small villages and raining on people in them causing distress. From what people can tell raining on people is all he does, but it is hard to tell because of his physical appearance, which is almost indistinguishable from a cloud in the sky (aside from his face) witch makes him difficult to keep track of. Because he is so hard to find and identify very few worship him, and the few who do are usually twisted and constantly looking up in the sky for him.
StoryHook: have someone who has been rained on mention him early on, and then make him appear randomly and harass the party (possibly giving some sort of negative effect).