Plastikman-Consumed

I don't know how obscure he is, but a lot of Mark Lanegan's solo stuff can be fairly dark. I would start with "Whiskey for the Holy Ghost".

A few bands you might want to check out are: Failure-especially Fantastic Planet, IMO by far their best album. Before they broke up Failure toured with Tool quite a bit and apparently were a favorite band of Maynards. A Perfect Circle did a cover of Failure's "The Nurse Who Loved Me". Don't...