I recently installed the Deathinitve Edition and played a bit but I had performance issues. So I installed the original Darksiders II. They seem to use the same savegame location as it was recognized but I couldn't load it due some "previously uninstalled DLC". So I created a new save slot. When I loaded it again and checked the DLC menu it says no DLC available. Shouldn't there be a few campaigns? I already uninstalled the Deathinitive Edition and deleted the savegame file. Still no luck.

I installed it on a different computer where no Deathinitive Edition was previously installed and the DLC showed up. So The DE must have messed something up, not even reinstalling did help.

OK, I figured it out. Darksiders 2 DLC uses a different .exe than the main game only. Somehow it could not be replaced during installation.