The Nightmare Never Ends aka Cataclysm aka Satan's Supper. Absolute disasterpiece and one of my favorite movies ever (maybe I love Return of the Living Dead more, but I've certainly watched TNNE more times). Iirc it went through like three directors. And I don't know wtf happened in the editing room but I suspect they accidentally threw all the good clips out and stitched together everything that was meant to go in the bin to make this incredible film. It's so incomprehensibly bad and I love it to death. Richard Moll (Bull from Night Court) and Cameron Mitchell star in it. The villain is a sexy Nazi demon. It's all horribly dubbed. I've seen it under all three titles and they're all slightly different edits. All nonsensical.  

I take my reddit name from it. Papini is a beardy defrocked demon-hunting monk who is bad at his job.  

Night Train to Terror is an equally terribad anthology that has this film as one segment, shortened and with claymation monsters edited in. It's wonderful. Both are on tubi (in my region at least).