Go down the path in the lower level to the left of the save point. Go to the end of the hallway and go to the next room. From here, go to the right across the land pieces to the lower door on the right. Next, in this room, throw one of each enemy into the fire (or get them in there by any other means). Go right into the next room. You can kill the hellbeast in this room (optional, but it could help?). Knock two guys up into hooks. Climb the new wall that appears. Go to the right and long jump across the gap. Perform Test Your Might. Go back across and go left this time, and wallrun up and wall jump up to the next door. Kill the enemies here. Go out the door to the left. Now, go to the new door that opened, and grab the axe that was finally created that drops in the middle of the room.
If you need any elaboration, I'll try to help.