If you'd like a few dark ideas for your fantasy games, I think you might like Little Things. It's got some good ideas, but it feels a little short to me. Since half of the content is available freely online, and the other half is mostly just tables, it also feels a little like a grab bag of stuff based around a general grimdark theme.
Still for BGG's first foray into published material, it's off to a promising start. I think one should consider Little Things more of a sampler of the dark content that Black Goat Games can and will output in the future.