Darksiders was supposed to come out for Linux a long time ago and never happened. The developers haven't forgotten about it, but it seems the issues are proving difficult to fix and they have been busy.
'Darksiders Warmastered Edition' just launched and the inevitable happened; someone posted on their Steam forum asking about Linux.
From their wording, honestly, it sounds rather unlikely that it will ever come (link):
MegalomaniacNGWe tried to pick up work on the Linux port but we couldnt fix the remaining issues it had. Instead we focused on Warmastered Edition. Maybe Warmastered Edition will get a Linux port one day. I am sorry for this but I cant tell you anything better right now.
Part of the problem is that the original person in charge of the port left the developer, so it got put further down their list.
That's one title I'm putting firmly in my 'forget me' pile, sadly.
Thanks Khudsa for posting it in our forum.