There's a good chance you own the original Darksiders, which automatically means you own the remaster.
THQ Nordic has finally released the PC version of the Darksiders remaster, Warmastered Edition. The publisher previously promised to give the game away for free to anyone who owns the original on Steam, and it has delivered.
If you own the original Darksiders, you'll automatically see the Warmastered Edition added to your library. You can still download and play either version, but keep in mind that saves my not always work between them.
The original Darksiders has been part of quite a few bundles over the years, not to mention massive discounts, and it's more than likely you already have it in your Steam account. I know I did, even if I don't remember buying it.
If you do not own it, however, you can pick it up for a massive 80 percent off. The Darksiders 2 remaster, Deathinitive Edition, is also on sale for 80 percent off.