There is the level with the red guy that leaves a trace of flames. Is it a devil? I think that is level five. You have to kill him to create the stairs!
Maybe it was that level, but if so, the stairs didn’t spawn after I killed it. There was only one enemy on the level, and I *think* it was black, not red, and I don’t recall seeing any flames, although it spawned right next to me so it wouldn’t have been able to leave a trail. I killed it immediately, and there were no stairs afterwards. Spent quite a while just wandering around the empty level, standing on every tile, bumping against the walls, wondering if there was a secret thing needed to advance. Pretty sure it was a bug, since an error message was emitted to the console.