This has ignited some discussions on Facebook and I thought I would post it here as well - after all, this is the sort of discussion that can increase interest in the site.
He's the closest I've read to "serious" literature or at least literature with darker themes, but of course he got into a whole lot of trouble for taking certain motifs of 19th Mormonism and exploring their darker, violent elements. I conducted an interview with him back in 2009 that I believe I posted here and should be in the Interviews section.
But yeah, outside of Evenson (who apparently no longer self-identifies as Mormon), I'm drawing blanks.
Je suis méchant.