I don't feel like it went off the rails completely but it just felt so rushed to me and it's like it had its good episodes but too many scenes if not entire episodes that left me feeling like they just wanted to get it over with. Plus a few loose ends that didn't really get explained such as who the god of fire is and his role in that world or a few others from earlier seasons. I feel like the show as a whole overall got worse as it went on after about season 3 or 4 though like I said it still had strong episodes here and there.