Yeah the 4th button is hard, but that's the last hard one. As soon as you hit the fourth button immediately backup [to the tile that was raised due to the removal of the torch], and then you have plenty of time to walk around to the 5th. Its floor doesn't open anywhere near as quickly as the other ...
Yup, you're right in thinking it's the south side of the pillar. The first time you go to that ledge (to the fourth button) and then remove the torch, a random archon appears. You kill him and then repeat the whole process, except as soon as you press the fourth button, you rush all the way around ...
Yeah, I cleared the room, but one spawns when you go press the 4th button in the sequence for the first time (the northern button, right beside the torch you remove). That's the archon that killed me. I reloaded and tried again and managed to stay alive, then performed the sequence again and had ti...
There are four buttons on the central pillar in the room with the two fire archons, but I only needed to press two to get the key (the east button, and the west button). I went back and pressed the north button and you can see it raises the platform in front of the southern facing button, but then ...