The sort of dark druid archetype is actually a pretty major point in the Baldur's Gate games, you can't go into a forest without tripping over a camp of them, and in BG2 there's definitely a section of competing druid ideologies becoming a side plot point, which I think is really interesting.
This reminds me I had a good Mastodon post on alternative biome druids from the Exilian account, which I meant to write into an article but never did. I should get back to that.